I think this happens because the one who purchased package unit and VAV diffuser is the client. If this stuff and integration BMS come from the Main contractor, they will do the loop check even for package unit. During commissioning stage, the unit package vendor should attend also and give all witnessing document. Btw there is two type of loop check, cold and hot loop check. Cold loops check to check electrical signal (digital and analog) and hot loop check to check interfacing signal (correct address from BMS to package Unit). I always ask BMS company to do check list for hot loop check before commissioning.
Great information. 100% correct on that these systems add more work to the bms integrator that hasn’t been allowed for and if anything a descope of the bms package is occurring. Off topic and sorry if this has been covered in another video, I feel it is also important to note that the packaged system to be integrated to the bms should meet the intent of the specification without any unconventional control practice by the bms. With more integration begin specified I feel the manufacturers need to make a more detailed document around the HLI component of their product and the internal logic needs to be freely available to include in the FD’s. Better documentation from the manufacturers would potentially assist with the planning of the end to end testing.
Shit, I forgot about that.. Good point. How often do we have an HLI to a packaged terminal unit, and then a couple of low level cables run from the riser to deal with the CO2 sensor and outside air damper. Yeah, the BMS contractor ends up doing a work around to make the packaged controls spec compliant.
Great video! We had the exact problem on a $4m BMS project in Sydney. I would note the following though. Any 3rd party HLI using Modbus, must be commissioned Point to Point, firstly from the HLI itself, then driving each point, including any diesel points. A 3rd Party HLI Schedule must be created. I'd probably argue for BACnet/MSTP or BACnet/IP, the HLI can be tested, and a handful of points tested, as there is no need to test every single BACnet object. Although I argue that each system must be tested against the FD, with a signoff commissioning sheet, as a whole system. If the system faults, then you need to go back to each BACnet point. Wholistically speaking though, does this actually save Commissioning time? Saves time for mechanical, of course, they don't have to worry about it. But I can't see a time/cost saving from the System integrator side, in fact, maybe even more time is required.
Nicely summed up Leo, Thanks. As you found, it's very easy to make a mistake in a Modbus mapping table. Agreed, it's impractical to point to point every HLI point. However, at least create a commissioning sheet and sign off the points that could be easily tested. Then everyone can see what was and wasn't tested, no misunderstanding. Or agree upfront that say 25% of the points will be end to end tested, another 25% sanity checked against the 3rd party touch screen or PLC.
Hi Bryce, Great video and I do agree that there are gaps in this process. However, I have to disagree with putting all the responsibility on BMS companies. I agree with the part that BMS companies to perform the full integration commissioning, but there has to be allocation in the specification for this. This practice will be costly and Mech contractors had to understand that there will be extra cost that they need to cover in BMS pricing. As you mentioned, precommissioning has to land in suppliers’ scope and they have to submit their point to point commissioning sheet proofing that they have tested everything on their side and it is working. Moreover, it has to indicate that the right point is linked to the right HLI point on their gateway. Then it will be BMS company responsibility to make sure everything is working as ONE system.
I am not formally putting all the responsibility on the BMS contractor. I'm sort of saying that the BMS engineer is the only person who really understands what is going on, which therefore puts them in the best position to highlight the gap. At the end of the day the BMS engineer is going to be stuck with getting the whole thing to work. Whether they like it or not it's going to end up being their problem so they may as well get everyone together and lead the solution. I am pretty sure we are both on the same page, I'm just describing it from a consultants point of view. Thanks for the comment 👍
Bryce Anderson thanks Bryce. This is one of the systems that is new and becoming more popular. It obviously will take couple of years to fill the gaps but we, as BMS companies, are always happy to help and get things sorted.
Great video. 👍🏻
Thank you 😊
I think this happens because the one who purchased package unit and VAV diffuser is the client. If this stuff and integration BMS come from the Main contractor, they will do the loop check even for package unit. During commissioning stage, the unit package vendor should attend also and give all witnessing document. Btw there is two type of loop check, cold and hot loop check. Cold loops check to check electrical signal (digital and analog) and hot loop check to check interfacing signal (correct address from BMS to package Unit). I always ask BMS company to do check list for hot loop check before commissioning.
Great information. 100% correct on that these systems add more work to the bms integrator that hasn’t been allowed for and if anything a descope of the bms package is occurring.
Off topic and sorry if this has been covered in another video, I feel it is also important to note that the packaged system to be integrated to the bms should meet the intent of the specification without any unconventional control practice by the bms. With more integration begin specified I feel the manufacturers need to make a more detailed document around the HLI component of their product and the internal logic needs to be freely available to include in the FD’s. Better documentation from the manufacturers would potentially assist with the planning of the end to end testing.
Shit, I forgot about that..
Good point.
How often do we have an HLI to a packaged terminal unit, and then a couple of low level cables run from the riser to deal with the CO2 sensor and outside air damper.
Yeah, the BMS contractor ends up doing a work around to make the packaged controls spec compliant.
Great video! We had the exact problem on a $4m BMS project in Sydney. I would note the following though.
Any 3rd party HLI using Modbus, must be commissioned Point to Point, firstly from the HLI itself, then driving each point, including any diesel points. A 3rd Party HLI Schedule must be created. I'd probably argue for BACnet/MSTP or BACnet/IP, the HLI can be tested, and a handful of points tested, as there is no need to test every single BACnet object. Although I argue that each system must be tested against the FD, with a signoff commissioning sheet, as a whole system. If the system faults, then you need to go back to each BACnet point.
Wholistically speaking though, does this actually save Commissioning time? Saves time for mechanical, of course, they don't have to worry about it. But I can't see a time/cost saving from the System integrator side, in fact, maybe even more time is required.
Nicely summed up Leo, Thanks.
As you found, it's very easy to make a mistake in a Modbus mapping table.
Agreed, it's impractical to point to point every HLI point. However, at least create a commissioning sheet and sign off the points that could be easily tested. Then everyone can see what was and wasn't tested, no misunderstanding. Or agree upfront that say 25% of the points will be end to end tested, another 25% sanity checked against the 3rd party touch screen or PLC.
Hi Bryce,
Great video and I do agree that there are gaps in this process. However, I have to disagree with putting all the responsibility on BMS companies. I agree with the part that BMS companies to perform the full integration commissioning, but there has to be allocation in the specification for this. This practice will be costly and Mech contractors had to understand that there will be extra cost that they need to cover in BMS pricing. As you mentioned, precommissioning has to land in suppliers’ scope and they have to submit their point to point commissioning sheet proofing that they have tested everything on their side and it is working. Moreover, it has to indicate that the right point is linked to the right HLI point on their gateway. Then it will be BMS company responsibility to make sure everything is working as ONE system.
I am not formally putting all the responsibility on the BMS contractor.
I'm sort of saying that the BMS engineer is the only person who really understands what is going on, which therefore puts them in the best position to highlight the gap.
At the end of the day the BMS engineer is going to be stuck with getting the whole thing to work.
Whether they like it or not it's going to end up being their problem so they may as well get everyone together and lead the solution.
I am pretty sure we are both on the same page, I'm just describing it from a consultants point of view.
Thanks for the comment 👍
Bryce Anderson thanks Bryce. This is one of the systems that is new and becoming more popular. It obviously will take couple of years to fill the gaps but we, as BMS companies, are always happy to help and get things sorted.