APC Transfer Switch... ebay.us/x557yY (check compatibility, affiliate links) StarTech 25U Rack... amzn.to/3cRfeH3 Let me know what you guys think, is this a good solution for not wanting lead-acid batteries? Or should I just invest in a proper UPS to reduce the possibility of equipment damage?
With your use and setup of this device, I would add a couple of WiFi smart plugs to the mix. That way you could swap power sources remotely. The plugs I use can be switched on/off from my phone anywhere in the world. They even have a scheduling feature that allows you to use them like a timer. You could create a schedule on the grid outlet to turn off during peak hours of solar. The same to turn off the solar outlet during the night etc. It could automate the process or give you remote manual switching options. Or both ;). I have often thought of hacking an inexpensive or used UPS and adding a large battery bank to it. I've actually come across a few different types being disposed of. More than likely because the battery inside was dead. I would think you could tap into the battery connections and expand them to hours instead of minutes of backup power. I never took the initiative to experiment, however.
@@thebuckeyedan The device has network connectivity already to remotely control it. So no need to add extra overhead with 2 smart plugs (which would be an additional $15 each). Just use Home Assistant to tie into the existing control interface as he already stated about controlling it through PHP commands.
@@thebuckeyedan For the UPS and adding batteries, it's much easier to get a server/commercial grade unit as they 'usually' have an external port on the back (SB50 connection) to add extending runtime. The other reason for using server/commercial vs residential is that they are designed from the ground up to run 24/7 on full load whereas residential ones are only designed to run about 10 mins. Those resi ones heat up fast!
@@korishan I have several smart plugs just lying around. I have no knowledge of the control interface in that unit. Your suggestion is definitely the way to go. A follow up video of the software and control solutions with it would be very informative. (fixed reply)
Just got a transfer switch for my solar power system, that switches between solar inverter and grid power, based on the voltage of the solar battery. Now I don't have to worry if my solar production will keep up with power hungry loads. This also allows my system to use as much energy as I can get from solar to power things before using grid power. Optimizing energy savings.
Interesting thing is there are inverters that do that as a function of them. Also with built in battery charging. They basically become an UPS with solar as a backup input for charging.
APC makes good stuff. I have a bunch of APC PDU's that run vertically at the back of our cabinets at the data center. 1 on each side of every cabinet, each fed by a different UPS system, and each server has redundant power supplies. The only switching is from commercial power to generator. The PDU's can have each outlet power cycled through a similar web UI, and I graph power usage in Zabbix. I don't know about your APC transfer switch, but it may support SNMP, in which case you could potentially graph power usage and whether it's from A or B feeds. I'd load Zabbix agents on those servers also and track disk, memory, network usage, etc.
I’m doing the same thing with the newer version of one of these. Switching is done based on some logic that looks at solar forecast sensors from home assistant through node red. Control of the ATS is via SNMP switch in HA. My grid source does go through an APC UPS while solar is direct from inverter/batteries. It’s been running great for the last year.
We used these units for years. Please note that the relays wear out after a couple of thousand switches, especially when using two different and unsynchronized power sources. In these cases every switch action creates a small arc inside the relays. I had an engineer of a different company (not APC) telling me that these units are usually designed for 40.000 switches, but when using unsynchronized sources the switches are reduced by half.
You do a real good job of making sure everything is "Squared away" and I really liked that dual source drop behind the racks. I'm also looking to increase automation and reporting for my battery banks, I have all my solar equipment with batteries crammed into a 2x2x2 foot cube.
Side note , Schneider Electric owns APC . You could make up a small off grid system just for running the rack with all the spares you have laying around . ?
Phase matching may cause problems despite the documentation. It's probably doing break before make switching so the supplies are never cross connected which is where the safe switching aspect comes from. A lot of people don't realise it but most offline UPSes phase match before transferring the load. Without phase matching the transfer to the inverter could see considerable current flows, potentially tripping its overload protection. Cheapie inverters can go bang, seen that happen in real life. Not saying this will happen, but it is something to consider.
A little more explanation since I've noticed YT doesn't like long responses. Switching power supplies will usually not cause any problems and this is the primary purpose of this ATS. The full bridge rectifier in the switching PSU will mean there is never a case where the reservoir capacitors are ever opposingly charged to the AC input. A capacitive dropper could present this issue but it would have to be unusually high current and that is typically not what cap droppers are used for anyway. This leaves inductive loads as being the problem because they can be opposing the AC input on out of phase switching and that's where things go wrong. LithiiumSolar does point out inductive loads so he's across the issue.
Built a unit does basically the same thing. With the exception that mine totally isolates all of the connections including the ground. Normal is grid power. Backup is inverter with inverter being priority. Turn on the inverter and it switches to it after a timeout delay. Turn off the inverter and it switches instantly to commercial power if available.
Appreciate that you shared the internals and a brief summary of what you think is going on inside. I had really wanted to see and get an idea of what was inside before buying as these are not dirt cheap, unless you sway for the 208 volt versions like I did... I just picked up three 2U size 208V units (AP7732) as I got them for an irresistible price (less then even just one 120V or 240V unit I could find!). The 120V and 240V units tend to run much higher, probably because of it being more useful in situations for regular users. Sucks APC does not release any internal info and loves to use in-house part numbers. Its odd, it looks like there are two switchmode PSUs, but then there are also those two larger transformers. From what I can see, it looks like those are just classic linear PSUs, but I wont know until my units arrive and I start reverse engineering them... I am suspecting the 24V section will be the same on all units, and maybe the transformers and isolation relays will be 208V... Hoping I will be able to modify it for either 120V or 240V operation (just applying 240V is a no-go because it is outside the voltage sense settings range, it tops out at 233V). I am presuming the MCU on the little SIMM looking card is for easy production of the units. I see there are blank spots on the board for 2 bank operation, so likely they made the MCU removable so that there is minimal component changes to make the different voltage and capability models. Despite the lack of info for internals of APC products, they are indeed always VERY well built and an abundance of great parts.
These have arrived finally. I have not done a full reverse engineering yet (desoldering components, etc) nor powered them up yet (I do not have 208V, but I do have buck/boost transformers). The 208V unit is a bit different, mainly in relay setup and sizes (higher amps, and parallel contacts on each relay - PC pin and quick connects) The white relays are used to isolate the inputs as you suspected. The coil voltage of these will be whatever your unit was designed for (208V in my case). Two per source, one for active/hot and one for neutral. All four of the white relays are N.O. SPST As soon as a source gets power turned on, the respective pair of these relays energize as the coil is directly wired to the respective input. The outputs of these then feed a pair of SPDT black relays. One for the active/hot, one for neutral. Source A is connected to the N/C contact, Source B connected to the N/O contact. The common terminals feed another pair of SPST black relays. The neutral then runs to the output sockets. The active/hot goes through the current sense loops and then to the output sockets. My units have two banks, so the total output goes through one loop, then it is Y split, and each leg (bank) has it's own loop. Hence the provisioning of 3 places on the board for loops. Each source's output from the white relays, also feed a SMPS and a stepdown transformer. Each is identical. The SMPS main section looks to have a single output, which goes through a diode. The other side of each diode is tied together, then this feeds LM2874N stepdown LMDMOS regulator setups. Before the diode combining, each SMPS does appear to also go through some resistors and to the area of the ADC, I suspect this is for individual SPMS output monitoring. The stepdown transformer looks like a single primary and dual secondaries, with the centres tied to ground (which on industrial transformers would often be identified as X2 and X3). Appears to be two small diodes acting as a full wave rectifier, and after filtering, each source is applied to a ADC0848 8 bit ADC (pins 3 and 5). There is however, one side of the unrectified secondaries that feeds off to more passives and then a 2222 transistor. I am going to take an educated guess and say that the SMPS is just to provide power for the logic/MCU and those step down transformers are responsible for the input voltage/frequency monitoring (I believe these units measure frequency, and maybe power factor as well, as part of a quality of power sensing). All that being said... It would seem the stepdown transformers and source isolation relays are unique to a model's intended voltage. Bypassing all the logic and directly controlling the relays is easy, however probably the easiest way to have the product's logic work is to feed the step down transformers 208V from a small boost transformer (or buck if going for 240V operation). The transformers are of course house part numbered, so not really obtainable unless you strip out another unit. I need to dig and reverse further, to see just exactly how it is sensing, and if there is a possible way to change it on the secondary side, without buck/boost transformers. There are a lot of 1% resistors in that area... would be great if they were in some divider arrangement and simply changing some to change the ratio would do the trick.
I have replaced all leadacid in my ups's with Lifepo4. Not using bms , just have an active balancer and a fuse. The ups takes care of over discharge, charge and other protections and i have monitored what it does and it is very accurate with the cut off voltages. The issue with having a bms is that it might cut off before the ups shutsdown and when mains is restored the ups won't automatically turn on again cus there is no battery available to it. So u have to manually press the power button to turn it on and that defeats the purpose of having a ups. This setup been running for more than 6months now and the battery backup from 12ah Lifepo4 is similar to 27ah leadacid.
Great video as always. Looking at the datasheet for the relays it looks like the delay in switching is about 15ms. The one concern I have is the relay datasheet does not say that the contacts are break before make, so there could potentially be a short period of time where both voltages are tied together.
This is a commercial product designed to switch between two different power sources. I would assume it's not shorting the sources together for a short period. That would be catastrophic...
I was originally thinking along the same lines, with a Sonoff like I used with the water heater a while back. I'm thinking though that I can control it with the Batrium and an RPI or something since it has such great network connectivity. We shall see - but yes, totally the goal to get it to eat up excess solar during the summer. So much gets wasted :(
No videos, but you can obtain the firmware from the APC website www.apc.com/us/en/product/AP7752/rack-ats-120v-20a-l520-in-10-520r-out/ Plug in the network connection and find the IP address. You can press and hold the display button to show it or check your router DHCP. The firmware download has a program that you input the IP and password, then it uploads the firmware via FTP. Very easy.
Important note re 8:24 : these types of double conversion UPSs are known as an online UPS, and a rare, and expensive! I doubt anyone here really uses one of these. The most common switches to battery and DC-to-AC conversion only after the mains power fails.
Good one! I use Progressive and Go-Power ATS(s) to auto-consume my off-grid solar power - e.g. as battery charges / inverters turn on, the ATSs automatically feed solar power to the circuits and then when the batteries run down the ATSs auto-switch back to grid. This happens twice daily BUT... I need APC UPSs to smooth out the 'switch' as it's not reliable for computer, tivo, and other sensitive equipment. This looks like it could replace a Progressive/Go-Power ATS+UPS combination - but it wasn't clear if you think it could do this twice daily automatically, and for several years at 365 x 2 = 730switches / year. Maybe if you do a followup you could share you're thoughts. In any case - thank you for so many great vids!!!
Is ok to use a UPS behind the ATS to avoid the blinking of power transfer. It might not be too bad on lights but servers don't like that, specially if you are running raid based applications.
How do you deal with 2 power sources where the respective grounds are not bonded together? My solar installation is TNS (earth rod) and the grid power is TNCS (earth provided by utility via grounded neutral wire in grid). While in theory the 2 grounds should be the same (they are both referenced to earth at some point after all), I've made sure to keep them separate within the house. In thinking I might have to install a galvanic isolator on the grid input to the ATS to isolate the ground. Any tips appreciated, thanks
It sounds like you need to consult an electrician... I don't know why you have multiple ground references. That sounds very wrong to me, but I'm not an electrician.
@@LithiumSolar it's more to keep the 2 systems completely separate. The solar is a DIY install and the grid system is the professional fixed installation that came with the house
Inductive loads pull huge surges at startup, could easily be 4-5x their rating, and could result in the relay contacts being welded in one direction after enough times.
You had mentioned that you had many LiFePo4 batteries sitting around and wanted to use them. Have you found it Ok to connect different brands of batteries together with out issue.
@@thechiefsway2618 I'm not sure what you're asking. This is a transfer switch, it doesn't use batteries. I have never put LFP batteries in a UPS. If you're asking just in general about the LFP batteries - yes, it's generally fine to connect different brands in parallel provided they are of the same chemistry, voltages, etc. You should never connect different brands in series.
@@LithiumSolarIn the video you said that now that you had this switch you could use all the batteries you had sitting around (I assume from the reviews). I assumed you would use those batteries with an inverter and charge controller to back up or power the server rack using the new switch. With all your reviews of different batteries I was asking if you had success connecting batteries from different brands together when the Brands do not recommend it.
That is a cool gadget especially for a small off grid system that’s still has a 120 V grid power input . I wonder if it can be utilized to start a generator at some way or between two inverters without grid power ? When you get a chance , check out my DIY solar videos , leave a comment, hit like and subscribe if you haven’t yet .May the solar be with you .😊
I'm not sure but that would be super cool if it were. It happily supports unmatched phase switching though so one of them would be non-zero during the switch.
I’m not sure you can hit the zero cross with mechanical relays. Large Industrial UPS’ do this with IGBTs as solid state devices are much faster so you can accurately hit the ZC point.
My magic box goes click, whir, thunk. I overbuilt it as it has a 4 pole transfer switch, timing relay on the inverter side, and circuit breakers on both inputs. It was built to originally handle inverters that could not take being tied to a house ground.
ARE YOU SHITTING ME!? I put lifepo4 batteries in UPS all the time. I've got at least a year on already. I have a thread on L1T forums. 12v lifepo4 has the same charge curve as lead acid.
APC Transfer Switch... ebay.us/x557yY (check compatibility, affiliate links)
StarTech 25U Rack... amzn.to/3cRfeH3
Let me know what you guys think, is this a good solution for not wanting lead-acid batteries? Or should I just invest in a proper UPS to reduce the possibility of equipment damage?
Absolutely nothing wrong with using old hardware. Keeps it out the landfill. As long as transfer times are
With your use and setup of this device, I would add a couple of WiFi smart plugs to the mix. That way you could swap power sources remotely. The plugs I use can be switched on/off from my phone anywhere in the world. They even have a scheduling feature that allows you to use them like a timer. You could create a schedule on the grid outlet to turn off during peak hours of solar. The same to turn off the solar outlet during the night etc. It could automate the process or give you remote manual switching options. Or both ;).
I have often thought of hacking an inexpensive or used UPS and adding a large battery bank to it. I've actually come across a few different types being disposed of. More than likely because the battery inside was dead. I would think you could tap into the battery connections and expand them to hours instead of minutes of backup power. I never took the initiative to experiment, however.
@@thebuckeyedan The device has network connectivity already to remotely control it. So no need to add extra overhead with 2 smart plugs (which would be an additional $15 each). Just use Home Assistant to tie into the existing control interface as he already stated about controlling it through PHP commands.
@@thebuckeyedan For the UPS and adding batteries, it's much easier to get a server/commercial grade unit as they 'usually' have an external port on the back (SB50 connection) to add extending runtime.
The other reason for using server/commercial vs residential is that they are designed from the ground up to run 24/7 on full load whereas residential ones are only designed to run about 10 mins. Those resi ones heat up fast!
@@korishan I have several smart plugs just lying around. I have no knowledge of the control interface in that unit. Your suggestion is definitely the way to go. A follow up video of the software and control solutions with it would be very informative. (fixed reply)
Just got a transfer switch for my solar power system, that switches between solar inverter and grid power, based on the voltage of the solar battery. Now I don't have to worry if my solar production will keep up with power hungry loads. This also allows my system to use as much energy as I can get from solar to power things before using grid power. Optimizing energy savings.
Interesting thing is there are inverters that do that as a function of them. Also with built in battery charging. They basically become an UPS with solar as a backup input for charging.
@@gravelydon7072 Yes, I've installed an Aims 6kw split phase inverter with that capability in a whole house solar system. It's a handy feature
APC makes good stuff. I have a bunch of APC PDU's that run vertically at the back of our cabinets at the data center. 1 on each side of every cabinet, each fed by a different UPS system, and each server has redundant power supplies. The only switching is from commercial power to generator. The PDU's can have each outlet power cycled through a similar web UI, and I graph power usage in Zabbix. I don't know about your APC transfer switch, but it may support SNMP, in which case you could potentially graph power usage and whether it's from A or B feeds. I'd load Zabbix agents on those servers also and track disk, memory, network usage, etc.
It does have SNMP support.
This is a cool use of an ATS. They are mostly used to power single PSU devices from multiple sources.
Yep, that's exactly what it's used for and is how I am using it.
I’m doing the same thing with the newer version of one of these. Switching is done based on some logic that looks at solar forecast sensors from home assistant through node red. Control of the ATS is via SNMP switch in HA. My grid source does go through an APC UPS while solar is direct from inverter/batteries. It’s been running great for the last year.
Can you share your config on home assistant. Struggling to set up mine
We used these units for years. Please note that the relays wear out after a couple of thousand switches, especially when using two different and unsynchronized power sources. In these cases every switch action creates a small arc inside the relays. I had an engineer of a different company (not APC) telling me that these units are usually designed for 40.000 switches, but when using unsynchronized sources the switches are reduced by half.
You do a real good job of making sure everything is "Squared away" and I really liked that dual source drop behind the racks.
I'm also looking to increase automation and reporting for my battery banks, I have all my solar equipment with batteries crammed into a 2x2x2 foot cube.
Side note , Schneider Electric owns APC . You could make up a small off grid system just for running the rack with all the spares you have laying around . ?
Phase matching may cause problems despite the documentation. It's probably doing break before make switching so the supplies are never cross connected which is where the safe switching aspect comes from. A lot of people don't realise it but most offline UPSes phase match before transferring the load. Without phase matching the transfer to the inverter could see considerable current flows, potentially tripping its overload protection. Cheapie inverters can go bang, seen that happen in real life. Not saying this will happen, but it is something to consider.
A little more explanation since I've noticed YT doesn't like long responses. Switching power supplies will usually not cause any problems and this is the primary purpose of this ATS. The full bridge rectifier in the switching PSU will mean there is never a case where the reservoir capacitors are ever opposingly charged to the AC input. A capacitive dropper could present this issue but it would have to be unusually high current and that is typically not what cap droppers are used for anyway. This leaves inductive loads as being the problem because they can be opposing the AC input on out of phase switching and that's where things go wrong. LithiiumSolar does point out inductive loads so he's across the issue.
That is VERY cool! I could see this becoming a standard addition to folks using server racks battery solutions.
Such a simple soultion that just works - thanks for sharing!
I have no idea as to most of what you described while looking inside this box. But I feel smarter for watching.
Built a unit does basically the same thing. With the exception that mine totally isolates all of the connections including the ground. Normal is grid power. Backup is inverter with inverter being priority. Turn on the inverter and it switches to it after a timeout delay. Turn off the inverter and it switches instantly to commercial power if available.
Appreciate that you shared the internals and a brief summary of what you think is going on inside. I had really wanted to see and get an idea of what was inside before buying as these are not dirt cheap, unless you sway for the 208 volt versions like I did... I just picked up three 2U size 208V units (AP7732) as I got them for an irresistible price (less then even just one 120V or 240V unit I could find!). The 120V and 240V units tend to run much higher, probably because of it being more useful in situations for regular users. Sucks APC does not release any internal info and loves to use in-house part numbers. Its odd, it looks like there are two switchmode PSUs, but then there are also those two larger transformers. From what I can see, it looks like those are just classic linear PSUs, but I wont know until my units arrive and I start reverse engineering them... I am suspecting the 24V section will be the same on all units, and maybe the transformers and isolation relays will be 208V... Hoping I will be able to modify it for either 120V or 240V operation (just applying 240V is a no-go because it is outside the voltage sense settings range, it tops out at 233V).
I am presuming the MCU on the little SIMM looking card is for easy production of the units. I see there are blank spots on the board for 2 bank operation, so likely they made the MCU removable so that there is minimal component changes to make the different voltage and capability models.
Despite the lack of info for internals of APC products, they are indeed always VERY well built and an abundance of great parts.
These have arrived finally. I have not done a full reverse engineering yet (desoldering components, etc) nor powered them up yet (I do not have 208V, but I do have buck/boost transformers).
The 208V unit is a bit different, mainly in relay setup and sizes (higher amps, and parallel contacts on each relay - PC pin and quick connects)
The white relays are used to isolate the inputs as you suspected. The coil voltage of these will be whatever your unit was designed for (208V in my case). Two per source, one for active/hot and one for neutral. All four of the white relays are N.O. SPST
As soon as a source gets power turned on, the respective pair of these relays energize as the coil is directly wired to the respective input.
The outputs of these then feed a pair of SPDT black relays. One for the active/hot, one for neutral. Source A is connected to the N/C contact, Source B connected to the N/O contact. The common terminals feed another pair of SPST black relays.
The neutral then runs to the output sockets. The active/hot goes through the current sense loops and then to the output sockets. My units have two banks, so the total output goes through one loop, then it is Y split, and each leg (bank) has it's own loop. Hence the provisioning of 3 places on the board for loops.
Each source's output from the white relays, also feed a SMPS and a stepdown transformer. Each is identical. The SMPS main section looks to have a single output, which goes through a diode. The other side of each diode is tied together, then this feeds LM2874N stepdown LMDMOS regulator setups. Before the diode combining, each SMPS does appear to also go through some resistors and to the area of the ADC, I suspect this is for individual SPMS output monitoring.
The stepdown transformer looks like a single primary and dual secondaries, with the centres tied to ground (which on industrial transformers would often be identified as X2 and X3). Appears to be two small diodes acting as a full wave rectifier, and after filtering, each source is applied to a ADC0848 8 bit ADC (pins 3 and 5).
There is however, one side of the unrectified secondaries that feeds off to more passives and then a 2222 transistor.
I am going to take an educated guess and say that the SMPS is just to provide power for the logic/MCU and those step down transformers are responsible for the input voltage/frequency monitoring (I believe these units measure frequency, and maybe power factor as well, as part of a quality of power sensing).
All that being said... It would seem the stepdown transformers and source isolation relays are unique to a model's intended voltage. Bypassing all the logic and directly controlling the relays is easy, however probably the easiest way to have the product's logic work is to feed the step down transformers 208V from a small boost transformer (or buck if going for 240V operation). The transformers are of course house part numbered, so not really obtainable unless you strip out another unit.
I need to dig and reverse further, to see just exactly how it is sensing, and if there is a possible way to change it on the secondary side, without buck/boost transformers. There are a lot of 1% resistors in that area... would be great if they were in some divider arrangement and simply changing some to change the ratio would do the trick.
Seems like something you'd use to cover for the case of UPS failure or maintenance.
Server ups usually work great with lifepo4, around 3.4v per cell
I use (new) dual AP4450A's in production at multiple sites in my enterprise. Great product. Can't think of any reason not to use older models.
Those look NIIICE!
That's a pretty cool idea dude!
I might have to try this with my off grid solar.
I have replaced all leadacid in my ups's with Lifepo4. Not using bms , just have an active balancer and a fuse. The ups takes care of over discharge, charge and other protections and i have monitored what it does and it is very accurate with the cut off voltages. The issue with having a bms is that it might cut off before the ups shutsdown and when mains is restored the ups won't automatically turn on again cus there is no battery available to it. So u have to manually press the power button to turn it on and that defeats the purpose of having a ups. This setup been running for more than 6months now and the battery backup from 12ah Lifepo4 is similar to 27ah leadacid.
Great video as always.
Looking at the datasheet for the relays it looks like the delay in switching is about 15ms. The one concern I have is the relay datasheet does not say that the contacts are break before make, so there could potentially be a short period of time where both voltages are tied together.
This is a commercial product designed to switch between two different power sources. I would assume it's not shorting the sources together for a short period. That would be catastrophic...
Very awesome, such a cool bit of kit.
You could add a wifi controlled power point on the grid side, and switch off grid when excess solar :)
I was originally thinking along the same lines, with a Sonoff like I used with the water heater a while back. I'm thinking though that I can control it with the Batrium and an RPI or something since it has such great network connectivity. We shall see - but yes, totally the goal to get it to eat up excess solar during the summer. So much gets wasted :(
Should've watched the whole video - neat you can switch it!
Just looked on eBay Australia and few options for
That is awesome. would you be able to do a little video with the firmware update procedure and where to get it from? :D
No videos, but you can obtain the firmware from the APC website www.apc.com/us/en/product/AP7752/rack-ats-120v-20a-l520-in-10-520r-out/ Plug in the network connection and find the IP address. You can press and hold the display button to show it or check your router DHCP. The firmware download has a program that you input the IP and password, then it uploads the firmware via FTP. Very easy.
Important note re 8:24 : these types of double conversion UPSs are known as an online UPS, and a rare, and expensive! I doubt anyone here really uses one of these. The most common switches to battery and DC-to-AC conversion only after the mains power fails.
I saw that same unit for sale on ebay and was tempted to get it. 😜
He had two of them - was still one left when I was done lol.
Sweet !! Nice video!
Would definitely be interested in the video controlling it with the script.
Good one! I use Progressive and Go-Power ATS(s) to auto-consume my off-grid solar power - e.g. as battery charges / inverters turn on, the ATSs automatically feed solar power to the circuits and then when the batteries run down the ATSs auto-switch back to grid. This happens twice daily BUT... I need APC UPSs to smooth out the 'switch' as it's not reliable for computer, tivo, and other sensitive equipment. This looks like it could replace a Progressive/Go-Power ATS+UPS combination - but it wasn't clear if you think it could do this twice daily automatically, and for several years at 365 x 2 = 730switches / year. Maybe if you do a followup you could share you're thoughts. In any case - thank you for so many great vids!!!
Is ok to use a UPS behind the ATS to avoid the blinking of power transfer. It might not be too bad on lights but servers don't like that, specially if you are running raid based applications.
Absolutely. I think this is intended to be used with a UPS anyway. That said, I haven't had any trouble with my servers when it switches sources.
Thanks for another awesome video.
I also have the same one. Mine looks like the same but it doesn’t have the led screen for the amps on it. Strange.
How do you deal with 2 power sources where the respective grounds are not bonded together? My solar installation is TNS (earth rod) and the grid power is TNCS (earth provided by utility via grounded neutral wire in grid). While in theory the 2 grounds should be the same (they are both referenced to earth at some point after all), I've made sure to keep them separate within the house.
In thinking I might have to install a galvanic isolator on the grid input to the ATS to isolate the ground.
Any tips appreciated, thanks
It sounds like you need to consult an electrician... I don't know why you have multiple ground references. That sounds very wrong to me, but I'm not an electrician.
@@LithiumSolar it's more to keep the 2 systems completely separate. The solar is a DIY install and the grid system is the professional fixed installation that came with the house
Well done! Learned a lot.Why not an inductive load?
Inductive loads pull huge surges at startup, could easily be 4-5x their rating, and could result in the relay contacts being welded in one direction after enough times.
Intéressant, merci pour le partage...
You had mentioned that you had many LiFePo4 batteries sitting around and wanted to use them. Have you found it Ok to connect different brands of batteries together with out issue.
The APC UPS are designed for lead acid batteries, not LiFePo4. That's why I haven't used them.
@@LithiumSolar Are you connecting diffirent brands of LiFePo4 batteries together in the new configuration.
@@thechiefsway2618 I'm not sure what you're asking. This is a transfer switch, it doesn't use batteries. I have never put LFP batteries in a UPS. If you're asking just in general about the LFP batteries - yes, it's generally fine to connect different brands in parallel provided they are of the same chemistry, voltages, etc. You should never connect different brands in series.
@@LithiumSolarIn the video you said that now that you had this switch you could use all the batteries you had sitting around (I assume from the reviews). I assumed you would use those batteries with an inverter and charge controller to back up or power the server rack using the new switch. With all your reviews of different batteries I was asking if you had success connecting batteries from different brands together when the Brands do not recommend it.
Great idea
any time there is a switching of a load there is a spike maybe those caps are for that
Maybe, not sure. I would kindof expect them to be larger if that were the case but I'm not familiar with how capacitors work on AC.
How long will it be before you wire a relay to switch the front button so it is an auto dump load? Oh ok at the end with a script right on.
If the script doesn't work, thinking a relay controlled by a sonoff like I did with the water heater a while back! So many possibilities!
That is a cool gadget especially for a small off grid system that’s still has a 120 V grid power input . I wonder if it can be utilized to start a generator at some way or between two inverters without grid power ? When you get a chance , check out my DIY solar videos , leave a comment, hit like and subscribe if you haven’t yet .May the solar be with you .😊
Does it switch at zero-crossing or just whenever? The "phase" comment sounds like it might be doing zero-crossing switching...
I'm not sure but that would be super cool if it were. It happily supports unmatched phase switching though so one of them would be non-zero during the switch.
I’m not sure you can hit the zero cross with mechanical relays. Large Industrial UPS’ do this with IGBTs as solid state devices are much faster so you can accurately hit the ZC point.
Very nice
nice! i need one too
Yea that’s cool
Magic box go buzz switch, buzz switch.
My magic box goes click, whir, thunk. I overbuilt it as it has a 4 pole transfer switch, timing relay on the inverter side, and circuit breakers on both inputs. It was built to originally handle inverters that could not take being tied to a house ground.
🤓👍👌🖖✌😎
ARE YOU SHITTING ME!? I put lifepo4 batteries in UPS all the time. I've got at least a year on already. I have a thread on L1T forums. 12v lifepo4 has the same charge curve as lead acid.
Yep, it works great! Until it doesn't :-)