Hvac hard start kits, how they work
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- Опубліковано 25 сер 2024
- In this video I explain the operating principle of hvac hard start kits, why potential relay kits are preferred, why the capacitor in an ac circuit does not send an energy boost to the compressor, and best practice on relay mounting.
WOW - thank you for properly explaining that the capacitor's job in this application is to enable greater torque through phase angle! I have run across way to many videos that incorrectly state that the capacitor stores and delivers a "jolt" of power to the compressor, which is wrong.
Also, thanks for pointing out the difference between kits that use PTC vs kits that employ a potential relay. As you indicated, the PTC type will not provide consistent starting function unless the start events have considerable time between them.
Wow, an A/C tech that understands phase angle. You are a rare breed, and I thank you for the video explaining how it works.
engineer.
@@kwm380 That explains it. Thanks!
Good Video I think some techs including me say send a high surge to get the compressor started is because it's easier for the homeowner to understand. Thanks for the explanation
Great video. In my experience, the word 'capacitor' conjures up all manner of theories -- all of which relate to DC voltage characteristics. Few know that we use caps for entirely different reasons in A.C. vs. D.C. but, then, you know that and did a terrific job of explaining this and driving the point home. Well done sir.
thank you! i can't tell you how many videos i had to speed to through to find the info you said!! love the writing parts, extremely helpful, because you can read them over and over while you talk and don't have to rewind to get the info! I'm going to reference your video when i post my fix for my AC.
Thank you very much for this excellent and easy to understand explanation. I own a Carrier 3T gas pack unit (48VG-B) and have tried to find information on Carrier's Hard Start kit that you reference here.
Oh and great explanation on the proper working of the start kit.
One way to explain phase angle is this: The capacitor causes a delay (a phase shift) in the alternating current in one winding compared to another, so that the motor *moves*. Each cycle gets to one winding before it gets to the other (that's what a phase shift means) so that every cycle keeps the motor going, pulling it first to one position and then to the next. Without phase shifts, those electromagnets would just hold the motor in a fixed position. Some AC motors need a capacitor only to start, because once they're moving, the recurrent pull of the AC keeps them moving. Others also need a capacitor to keep running.
Excellent explanation!! I'd love to see a follow-up video explaining how the phase shifted current is applied to the starting winding to produce the torque to get the compressor spinning.
Thanks for the comment. These kits work well and I have them on all my units and I keep spares.
Now that is a good question, Sir.
Thank you very much for the GREAT explanation of AC circuit phase and capacitance!
Now I understand how the 5 2 1 kit I put on the compressor works to reduce the start-up spike
(the spike is not a big deal when we are on utility power, but when the house is on generator, the genset really hates the scroll compressor, vs the old heat pump reciprocating compressor) 32S-3 !!!
Get a Hyper Engineering soft start and your generator will barely notice the compressor.
You just taught me why one of my customer's generac control board keeps blowing. He's got one of them whole home backups and it's hooked up to his two 5ton condensers. High voltage passes through the generac board before going to the load.
Easy to recognize:
Run caps are housed in metal cans to help dissipate any heat produced over long periods.
Starts caps are housed in black plastics for short term duty.
Max voltages are also different besides Run caps use lower uF values to feed the additional winding a precise current value to match Main winding.
Brilliant explanation. There are a lot of guys posting videos, some of whom are professionals, who are driving that misinformation about what the start/run cap is doing. Partly it's due to the inability to explain it quickly, but I suspect many never understood it.
I think it's because it's easier to tell the customer that the thing "sends a big boost"
Concise useful info no waffle or BS ... many thanks Dude.
Very informative explanation. I hope you still read comments as I would love your input. I personally use the AMRAD TES 5 - 2 wire kit with built in potential relay for the very reasons you describe regarding kits with PTCs. (Florida Lots-o-heat with high humidity). A neighbor recently suffered the dreaded seized up compressor condition. It's stuck well (not shorted to ground and not in thermal protection) (windings have resistance) Normal Hard start kit/s failed, reversing run/start, and rubber mallet therapy and various combinations all have failed to free up the compressor. (we are leaning heavily on mechanical failure). It's in the hopper to be replaced, however, this could take week/s. So thought experiment as there is nothing to lose: Normally procured uF hard start kits on a high end use approx 400 uF capacitors to generate the phase shift allowing for more current to produce the extra torque on the compressor. Have you ever used or what do you think about let's say a 1000uF capacitor introduced into the circuit for 1-2 seconds?
Sorry, I don't have any experience with that particular problem.
Thanks for taking the time to help us
This is exactly what I needed!! Great lecture, sir. I bow before you :)
Same. This was a great explanation
Glad to see after watching 4 or so videos someone addressing the role of capacitance with regard to starting a "single phase" motor. I do however respect experience, even if someone's theoretical understanding is "lacking" i still watch and learn what they have to offer. With regard to the "bleed off" resistor, it's function may be better understood by the relationship of LCR circuits, again mostly addressing phase shift, by adding a purely resistive component the curve of the phase angle is made more useful over a wide range of inductance (which occurs while the rotor is anywhere from "locked" to run speed) but yeah sure, we can call it a bleed off resistor. But wouldn't calling it a bleed off make more sense in a DC circuit.......
The value of that bleeder resistor is such that it essentially does nothing with respect to the circuit. The R of the LCR is the winding resistance of the motor. And, yes, you need a bleed off resistor in an AC circuit as the capacitor can become charged just as easily.
And you can not test the mfd if the bleed resistor is in the circuit. You have to remove it or the cap will always read defective. Just my 2cents. No charge.
In a resistive circuit (heaters) the voltage and current are in phase. In an inductive (motor) circuit the voltage leads the current by a quarter of cycle (90 degrees).
In a capacitive circuit the voltage lags the current (90 degrees). This shift ruins the torque. So the capacitor accomplishes Power Factor Correction. Thus improving the torque.
Thank you
Very good information
Yes it shifts the phase you said it correctly good video
If the hard start kit goes bad then the startup current would be about the same as the listed LRA. If you measure the inrush current and it's 50%-70% of LRA then the kit is working.
Good stuff...
Will they shorten the life of the compressor?
What a great explanation
I just purchased a hard start kit and it’s a Kickstart 2 wire. I noticed it had one less wire from the previous one that blew up on me.
Can that Phillips hard start cap go bad ? Is there a way to fluke meter to test if its gone bad. Also can one actually just bypass it on an outside AC unit ? ( ie wire nut two red wires together that used to go to Phillips hard start cap )
We have the 5-2-1 three wire kit, 5:30 BUT, what we want to know is… we Also have the Turbo200 on or AC unit… So do you hook up the wire that would go to Common on the unit capacitor to the Orange 🍊 CPT terminal of the Turbo200 instead..???🤷🏻♂️
If your customer is having lights dim on start up install a start kit. If they continue to dim check the breaker box, tighten all connections and check at the disconnect and unit as well. These are not I repeat NOT for 3 phase compressors. The Kick-start got a bad name when they first came out due to the relay hanging up and burn up compressors. Now they have a fuse to prevent that from happening. I only use the 521 on service. I get the factory spec. for new installs.
Informative video, thanks.
Thanks so much, great info.
Very good info thank you
Thank you, Thank you, Thank you!
Stan, thanks, I did forget to mention about the back emf kicking the relay out.
Question for ya. I've heard from multiple different experienced techs that you must use OEM Trane Hard Start kits (start cap and relay). I don't understand why that would be if they do the same thing. Only thing I could imagine is that maybe Trane compressors have a slightly different start sequence?
Is this a real thing or just one of them "beer can cold" things you hear from the older guys?
I suppose Trane doesn't want people to screw up and expose them to warranty claims.
Can you oversize a start capacitor? My 9000 btu scroll compressor has a long pipe run, so I want to give it a little boost. The boost kits have quite large caps, for a small compressor.
Yes it can be oversized. I think there are some RV sized kits.
Hello I was wondering what you thought of 2 wire sp5 ptc relay capacitors they start anything from 1/2 hp and up , I have been using them with great success over 15 years Regards Rob
My only beef is when people used a 5-2-1 or a 2 wire to replace an oem start kit that came from the factory and they have different ratings and people thinking it’s ok to use
Excellent info
I mean in series it will always limit current and that's how those work they just let more current thru than the smaller capacitor
Pretty good how ever the capacitor cancels out the inductive reactants of the start winding and allows it to draw more current
Giving greater torque, The bleeder resistor is to discharge the capacitor so that on shut down of the compressor there is
No arc at the closure of the start relay causing it to weld stuck, it would be good for you to show how the start capacitor
Is removed from the circuit with a momentary current draw wit your clip on ammeter and to verify it’s operation.
If you disagree with my explanation please let me know
In most applications a bleeder is across a cap to ensure anyone working on the system does not get a nasty shock even when power has been long removed. In this case, of a start boost capacitance, your explanation is the applicable one, as without bleeding off any charge, the cap would discharge as soon as the contacts closed with potential of welding the contacts. Safety is not the issue in this very specific application. I am grateful for your pointing out the real reason for the bleed resistance as I had assumed it was for the usual purpose of not leaving lethal voltages hanging around in an un-powered circuit.
My start cap failed, so I fixed it. Next week condenser fan died fixed it, one day later my hard start kit cap literally blew up. Idk what's going on anymore.
No mention as to if a Hard Start Kit (which adds circuitry in the kit) needs to keep the current relay ( I have a current Carrier HN51KC024 Coil relay in the compressor unit box) and add the 2 wire black wires to the "C" and Herm spade connectors or remove any current coil relay. ALSO, do I get a 2-wire kit or a 3 wire kit and is it universal enough as not to worry about an specification Hard Start to purchase (ie. specs of capacitance, etc.).
Suggestion?
If I understand your question right, if you're adding a new hard start kit you must remove the components of any old hard start kit.
@@kwm380 It does NOT have a CURRENT hard drive kit inside the A/C unity. Here's the situation. Presently, there is my HN51KC014 coil relay and my Run Capacitor in my compressor's unit. I want to ADD a hard Start Kit in my Central A/C compressor unit outside. Opening the cage's access, one can see the capacitor and potential relay inside which both came with the A/C 15 years ago. I was wondering if there was a specific hard start kit and if I jst add it to the existing components as I don't know much about the hard start kit. If so, how is it hooked up with or without the current relay in the system. Thanks guys.
@@jerrymontalbano3222 I understand you now. You're speaking of your contactor which is different than a potential relay. All that stuff stays. I recommend the Kick Start brand Hard Start kit. They are easy to install. Just 2 connection to your run capacitor. Select the one that fits your size unit. They have two sizes.
@@kwm380 So, it's a "one-size-fits-all" hard start kit which is installed in the compartment, and the two black cables connects to the Common and the Hern spades on the Run Capacitor. Right? I was wondering what happens to the current potential relay HN51KC024 which is there. I was curious, because I've seen a video with the 5-2-1 hard start kit which has three cables and perhaps connects one of the cables (they have red, yellow and black cables, I believe) which connects to a "potential relay" (whether it's bought with it or as an existing one). I was also concerned about the kit coming in different specifications which must match exactly what the run capacitor, potential relay calls for.
@@jerrymontalbano3222 No it's not one size fits all. Kick Start makes 2 or 3 different sizes. If you have any doubts about how to do it I advise you to get an electrician or HVAC pro to do it for you.
Good video. I can, however, see a possible problem with these. The problem is this, what happens when the points on the relay stick closed and the cap is not removed out of the circuit. I can see one of 3 things happing. first and hopefully the circuit breaker or fuse will blow. Second the cap it's self will blow or 3r you wind up with a burnt-out winding on the compressor.
I agree with your summary of the consequences, but why would the points stick in the first place? The only stress on the contacts is at the instant of opening, never on closing, and even on opening the potential difference between the booster cap and the run cap is zero as they have been in parallel up until the moment of opening, so there is reduced chance of arcing. A failed relay coil would result in the scenario you pose, but relays are pretty solid.
@@pafmelb1927 Here is my understanding. With the hard start in the circuit you have that extra phase shifting going on. Remember there is a great deal of current flowing through the hard start capacitor. As soon as the hard start is taken out of the circuit the phase shifting changes as does the current flowing through the capacitor. This sudden change of capacitance coupled with the inductance of the windings in the motor could cause a thing called kick-back reactance.
@@neutrodyne So you're saying the inductive spike caused by the instantaneous change in current which was due to the sudden removal of the hard start cap would/could be enough to form an arc which could weld the contacts as they try to open? I had not considered the voltage spike caused by the dI/dt in the start winding, but was only looking at two parallel capacitors being separated. Thanks for broadening my take on it.
So when adding a start kit like the 5-2-1, is it just merely increasing the phase angle? I can’t wrap my head around why the starting amps are lowered so much when adding these things. I know they work, I put one on my 2 ton A/C at my camp and reduced the inrush current from 56 to about half that so my generator can run my A/C now. Wouldn’t the proper size capacitor to begin with accomplish this? Are these things needed to simply correct the manufactures short coming?? It seems like it is flawed engineering if you need to install one of these.
Exactly my thoughts and questions
@@heistmasters6665 , I've been pondering this for a long time. I'm guessing that too much start up torque could have an adverse affect on motor mounts or cause metal fatigue somewhere because of the increased torque. I noticed my unit pretty much snaps on now. My luck I will be ripping something apart since everything is made lighter and cheaper. Hence, maybe these engineers know what they are doing and factor that in. Still, it is interesting how increasing the phase angle increases the start-up torque and reduces the start-up amps. The laws of leverage at play here I guess.
A compressor is a motor, and is subject to inrush.
When voltage is applied to a motor, the motor coils essentially look like a short circuit in the first few cycles and diminish as the motor comes up to speed.
In a purely inductive circuit, current lags voltage by 90 degrees.
Real power is determined by how in line the voltage and current waveforms are.
The compressor saver is temporarily applied to the circuit and brings the phase angle between voltage and current back into alignment.
The capacitor allows more real power to be consumed by the compressor.
Less current is drawn since the voltage is in phase.
Higher current results in more heat due to I^2*R losses which is what stresses and damages components.
A/C manufactures likely don't see it as a necessity and more of an added cost.
They'd rather stick to simple and traditional designs.
Also, the A/C techs and manufacturers probably make a decent amount selling it after the fact.
I was just quoted $453 for a compressor saver which is what brought me here.
Can you explain the symptoms if the start capacitor or relay were to go bad? (Besides the answer "compressor won't start").
The best way to tell is to measure the start current. If you don't have an instrument for that examine the capacitor. When they fail they usually blow a seal out the top.
Where can I purchase RVA413R relay
Sounds like you know what you’re talking about. Thank you for posting! I have a question for you on the 521 start kit. I bought the 3 1/2 to 5 ton 521 start kit but after purchasing realized that my 4 ton (Carrier with Copeland Scroll compressor) unit OEM start kit (found it digging on internet for Copeland specific compressor model) actually has the capacitor (microfarads were identical) that is on the 1 to 3 ton 521 start kit! I went ahead and got the smaller 1 to 3 ton start kit even though it’s not what 521 marketed for my 4 ton unit. do you think I did the right thing? Start up amps went from 108 to 58 with the 3 1/2 to 5 ton 521 kit and 108 to 78 amps with the 1 to 3 ton start kit which is what’s running on it right now. Thanks again for the great video!
I don't think the start capacitor value is all that critical. Some OEM's have one kit for all sizes of compressor. Sounds like what you did is working well. It's essential that the relay switch the start capacitor out of the circuit which it sounds like yours is.
“Phase shift” to normal people = “big jolt of power”
Might be what they think - but it ain't the truth. Torque and power are not the same thing.
Is it producto work ?
So the hard start capacitor takes all the torque out of the compressor when it starts and makes it easier on the generator?
The kit reduces the current necessary to start the compressor and it does make it easier on generators.
It's all about power factor correction.
I think you forget to explain how the motor's "Back EMF" voltage that cause to drop the hard start kit relay out of circuit as soon as motor is running.
I believe "back EMF" is created because the Run and Start winding are located 90° or so apart.
When the magnetic rotor is spinning it generates induced voltage through the Start coil winding.
Where I am not super clear is the difference between a motor with a "Start cap" vs. a "Run cap": different construction!
I guess the "Run cap" creates additional Run torque because its winding is precisely aligned to help torque production from an artificially phase-shifted voltage vs. "Start winding" is roughly positioned to help orient (left or right) the rotor while static but is not positioned or sized for constant duty so it is cut-out quickly.
Fridges: use Start caps...
AC comps, blower fans: use Run caps.
@@glasser2819 The video explains it wrong anyways. I mean, he's right, it creates a phase shift so you can create a rotating force (torque) so the motor can run. Capacitors are basically batteries that store power for as long as it is supplied and discharge quickly once power is cut (via resistor or through the motor windings or really any wiring.) They do store a charge at a constant voltage (DC) and they do the same on A/C except they also discharge because the voltage fluctuates. As the voltage increases and decreases (remember AC sine wave) the current is actually increasing and decreasing in the capacitor 90 degrees out of phase (cosine) which is what starts single phase induction motors. Otherwise, you don't have a rotating magnetic field and no squirrel cage to turn. The run capacitor is designed for continuous use and helps smooth out the fluctuations so the motor can run at a constant torque, more for efficiency reasons but they're definitely built differently to handle the use and not burn out like a run capacitor. Same exact principal behind both, just two different constructions with two different uses. The run capacitor will still create a slight phase shift but it's in relation to the fluctuating AC sine wave coming it, it just helps the windings produce torque at the exact right time to keep it all spinning when incoming power invariably wobbles from time to time. The start capacitor just does it at a more defined time with a greater inrush to help get things moving before dropping out of the circuit.
@@etherealrose2139 That model of what a capacitor is good for DC, but it omits the correct behaviour when dealing with AC. In this application it's ALL about phase shift and what that does to the torque, the time to get up to speed, and the current draw when one winding gets more phase shifted current and nothing to do with "stored energy". GWM's explanation is basic, but also correct.
Oops - the above was intended to be a response to Tate Dillow in a post above - somehow got attached to Stan's post. My clumsy. PAFMelb
Great video! FYI, I just bought a Kickstart on the relay now says "This side up".
So in other words is that phase shift is actually a big jolt of torque..?
pls help, how do i know which ac hard start kit for my residential ac my is lennox 5 ton
Kickstart ks-1
@@kwm380 Thank you so much
Anyone know which style the Packard TQS6 two wire kit is? ie PTC or relay or both?
That is PTC. I would avoid.
questions:
1) why dont manufactures put hard start kits in their AC units?
2) what effect do hard start kits have on starting amperage draw?
I think they don't put them because of the cost, even though it's not that much. The typical start amp draw with my kits is about 60% of no kit.
thanks pro 😘
Hi,
I was thinking to get a 5-2-1 Compressor saver kit but not sure which one would go with my unit.
According the MFR, there are 3 different sizes and here is the confusing part, my unit is a 59,500 BTUH unit (5 ton) but my Run Capacitor is only 80 uF MFD. The model for 5 ton units (CSRU3) states 270 - 374 MFD. Should I go based on the Compressor tonnage or by the run capacitors uF MFD?
The unit is a Amana Heat Pump Model RHE60A2B
Run Capacitor:
Mars 12199 - 80 uF MFD x 370 VAC Genteq Replacement Capacitor Round # C380R / 27L63
Hard Start KIT's:
5-2-1 Compressor saver kit
CSRU1 = 88 - 108 MFD for 1-3 Tons
CSRU2 = 189 - 227 MFD for 3.5-4-5 Tons
CSRU3 = 270 - 374 MFD for 4-5 Tons
The 5 ton unit would need the largest 5-2-1 kit. The MFD shown are the start capacitor which is different from your run capacitor.
one question: the capacitor that i had on my system is a 45/7.5...can i use a 45/5? my capacitor has already been changed before, so no sure if i had a 45/5 on there before. how do i check my system to know what i need, do any of the stickers show this or i can figure out using the numbers on the stickers?
You can Google the parts list for your compressor. If you find the part number for your capacitor you can search Amazon or ebay and find the proper capacitor rating.
@@kwm380 where do i find the compressor part number so that i can find a parts list...is it on the compressor it self or the stickers on the outside body panel?
I have to wonder if the OEMs are making these kits, why aren’t the units coming with them from the factory? Any idea?
I think it's cost, like any accessory.
what is 5-2-1?
It refers to the terminals on the relay; also the name of a kit.
What kit lowers the in-rush current to the compressor the most?
I'd recommend either a Kickstart or a 5-2-1
I have seen these start kit capacitors mentioned by people that are using them to get their RV air conditioners going because they may be using a generator that can't put out the peak startup wattage. But I never hear about them being used for other appliances like say a refrigerator which I believe also needs much higher wattage when it first starts up. Also, many appliances and tools have a high startup wattage so I was wondering if these hard start kits would work with other devices. I would imagine that an air conditioning pump and a refrigeration pump would be very similar to some degree. I always thought that these start up kits work by storing up a charge and then releasing a high wattage output to get the air conditioner past the startup surge. It sounds like you are saying that this is not how they work. Unfortunately my knowledge with regards to electrical motors and electronics is very basic and I don't exactly understand how they do work from your video. But I watch videos like this to learn. Thanks.
MusicByJC most likely the refrigerator has a start capacitor on it with a Klixon overload.
Good day sir, could you use a start capacitor without a relay? It's for starting a stuck ref compressor that was repurposed to inflate car tires. It was working great until it was used to inflate an inflatable pool. How many microfarads should it be and how will it be wired? Thank you very much?
You can do that for a few seconds but unless you remove it from the circuit manually the start capacitor will overheat and blow up. I don't know anything about your motor so I can't speak to MF.
@@kwm380 Sir it's a DD51C11GAX6(RSCR) reciprocating compressor, Panasonic. I don't intend to connect it permanently to the circuit, just to get the motor unstuck. What microfarad value should I use? I don't know if it will work I think the piston got stuck when it has been running for more than 30 minutes. Is it worth the effort or am I just wasting my time? Thank you
@@raymundsantos2324 If the piston got stuck then likely it was due to overheating due to excessive running time. If you are talking a kiddie pool then the run time to fill that is likely not more than the time to fill a tyre, but if you mean a big pool then likely the pump is U/S rather than the motor driving the pump. Increasing motor torque (even temporarily) won't necessarily result in either the piston freeing, or if it does, that being a lasting fix if the cylinder or piston are damaged. Besides, a tyre pump is intended for high pressure low volume. A pool is best served with high volume low pressure.
@@pafmelb1927 thank you very much!
@@raymundsantos2324 No refrigerant = no lubrication?
They off cet the sign wave to some degree you would need an oscilloscope to actually see how much the off cet is
*offset and *sine wave
FTFY!
It's unclear to me why start circuits on new compressor/condenser units are not properly sized from the factory, such that it's a good practice to supplement/modify them in the field. Adding too much phase shift would be counter-productive would it not?
It’s a cost thing. If it cost $10 to add a start kit at the factory it’s too much. Most manufacturers have a recommended Oem kit as an option.
Does the start capacitor have polarity? Or can it be installed either way?
I think they can go either way
That was excellent sir. Pls can it be used on a simple ductless split AC unit? Thanks
Chick Edwin I would check with the manufacturer to see if they have one for the unit. It may already be on the board.
@@actechformallyyomama746 OK and thanks for your reply Sir
I have a Lennox xp17. What hard start capacitor do you recommend for this unit?
It depends on the size of your xp17. 5-2-1 has two different sizes depending on your unit capacity.
kwm380 ok thank you.
Is 5-2-1 some description of the design? I thought it was just a brand name of a company.
5-2-1 refers to the terminal numbers on the relay. The company borrowed that designation I guess.
These hard start devices are so cheap compared the cost of an A/C unit, why don't manufacturers just include them on the units? At mass production, it would literally be a few dollars per unit.
I think a couple of reasons. First is cost. They try and save on every washer and screw. This probably cost the manufacturer $10. Second, if they make the units last longer it reduces replacement sales. That is the conspiracy theorist coming out in me.
If it’s just adding more capacitance in parallel, how is it different than just using a higher uF cap? Is this just obfuscated marketing for “more capacitance”?. You could add a bleeder to a slightly larger cap than normal and not buy a more expensive “hard start” kit that does the same thing. From your explanation that’s what I see.
You can't just add more uF because the start cap needs to be removed from the circuit after the compressor is running. The compressor motor generates a back voltage (back electromotive force) when it is running. The relay senses this and switches the start cap out of the circuit. If you just added more uF with no way to take it out, the motor would not run optimally as it is designed to do with the proper run capacitor.
@@kwm380
So these also come with a mechanism to open their circuit after starting?
I’m still not clear, I probably need a diagram. These go in parallel with the start or run cap? It sounds like the start cap. Doesn’t the start cap already take itself out of circuit? Can you piggy back on the existing cutoff circuit?
@@ericrandall3539 yes. The little box of the 521 kit for example is a relay that switches the capacitor out of the circuit when the motor starts.
so would one kits work on the small RV rooftop A/C units?
I believe they make small ones for RVs.
I have installed one and they work quite well. Especially for use with a generator.
How do you determine if the hard start kit is bad?
A couple of ways. When the cap blows it generally blows out the top vent.
I like to check the startup current with my ammeter. When the kit is working the startup current will be much lower than the LRA rating of the unit, like 60% of LRA. If the kit is bad or not hooked up right the startup current will be close to the LRA rating.
kwm380 thanks
Do you mean starting capacitor works as power factor correction ?
I suppose it does alter the PF for a brief second but that is not really the intent.
@@kwm380 Does it works when the compressor starts up a few seconds and disconnecting it from the circuit ?
@@wadib3eed7 Yes, the compressor generates a voltage that makes the relay open after a few seconds disconnecting the start capacitor.
@@kwm380 Potential relay works as open delay by using EMF but takes the voltage from motor at starting up time, not directly from the main power, is it right ? for this reason they use potential relay to give a delay time before kick out the starting capacitor ?
@@wadib3eed7 Yes the EMF to open the relay comes from the motor when it's running, not from the 240volt power source.
i want what u are on, if you are really serious.... WOWMAN
Eeeeehhhhhh.....