InRow AC ACRP102 Runtime Balancing

[BillP]

This question was originally posted by Peter on APC forums on 5/22/2017

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Hi,

I have 2 InRow ACRP102 Air Conditioners in a HACS and am trying to implement runtime balancing between the two. I have tried to configure them as per the Operations Manual, but so far no luck with an automatic changeover of roles.

Can any one help? I can provide more detail and even the logs if it would help figure out where I'm going wrong.

Regards,

Peter

[BillP]

This reply was originally posted by L2SupportServices-Cooling on APC forums on 5/23/2017

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Hello Peter. A few things to check. First under the group configuration, make sure there are two units in the group. Put 1 backup unit but leave the "full RP backups" at 0. Make sure to enable the runtime balance on the units. Also check your Type. If the units are in InRow mode, there is no lead/lag on the units. The units will need to be in HACS or RACS (this depends on the setup of your room. If you have a hot aisle containment system then use HACS. If not use RACS. Next go under the unit configuration and make sure the "role override" is disabled (this will make a unit the primary and run it all the time if it is enabled). Lastly go to the runhours page and clear the runhours for the compressor and the system to get both units to 0. This will get the units on the the same starting point for the runtime balance. The first unit should run for 72 hours then switch over to the second. That one will run for around 144 hours (72 hours past the other) then switch back to the first. They should then continue the switching off about every 6 days form there.

Thank you

[BillP]

This reply was originally posted by L2SupportServices-Cooling on APC forums on 5/23/2017

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I am sorry I missed that you are already in HACS so please ignore the Type setup.

Thank you

[BillP]

This reply was originally posted by Peter on APC forums on 5/23/2017

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Hi,

Thanks a lot for your prompt response. I had already done most of what you've suggested except I only reset the system runtime, not the compressors'. Let me reset them both to 0 and wait for 72 hours then I will let you know how it goes (fingers crossed it works!).

Thanks again and best regards,

Peter

[BillP]

This reply was originally posted by L2SupportServices-Cooling on APC forums on 5/24/2017

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Thank you Peter. Let us know how it goes.

[BillP]

This reply was originally posted by Peter on APC forums on 5/29/2017

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Hi,

So after following your advice and waiting 72 hours, the AC units still did not changeover automatically. Now the primary unit has an error "No backup units available exists" but I think the A-Link connection is okay (when I disconnect it I get a "Group communication lost" warning). I have attached latest config files and event logs for both AC units and I would really appreciate it if you could go through them. Maybe they can help pinpoint the problem. Please be in touch if you need more information or clarification about the ACs.

I await your valuable feedback.

Thanks and best regards,

Peter

[BillP]

This reply was originally posted by L2SupportServices-Cooling on APC forums on 5/30/2017

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Hello Peter. From the logs it shows unit 3 as in Standby. This means the unit is manually turned off and will not come on. Make sure to put this unit as on form the front screen. Both units need to be on for then to start the lead/lag. When you look on the front screens one should say on and one should say backup for them to switch over.

Thank you

[BillP]

This reply was originally posted by Peter on APC forums on 5/30/2017

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Hello,

Please explain how will they change roles if they are both ON? Will that not result in similar runtimes? Or it can be ON without actually supporting the load?

In the menu presently there are only ON/STANDBY options available. And since the data center installed capacity can be supported by one AC unit, we wanted one unit to run while the other acts as a backup, ONLY coming ON when the primary AC fails or cant handle the installed load for whatever reason.

Thanks

[BillP]

This reply was originally posted by L2SupportServices-Cooling on APC forums on 5/31/2017

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Hello. The Standby mode is where the unit has been manually told to stay off. It will never come on to support the load until it is manually turned to "ON" from the front screen. When the unit is turned to "ON" it will be able to support the load. When the unit is by itself and in the ON mode it will run to satisfy the settings that were put on it to cool the room. When the unit is in a group of units with a backup enabled, the units will look at all the units in the group that are turned to ON and will choose one to be in backup mode. This unit in backup mode will not cool unless it is called for to start cooling by either 1. a unit that is cooling that has failed, 2. the units that are cooling are not able to keep up with the load so it will call the backup unit to come on to assist. (you will need to make sure load assist is enabled on the units under group config.) or 3. the runtime balance is enabled and it has reached the time to switch over. This will select another unit in the group to go to backup and turn the backup unit on.

Thank you

[BillP]

This reply was originally posted by Peter on APC forums on 5/31/2017

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Hi,

And to enable a backup in the group of units I just configure Num of Units & Num of Backups in the Group Configuration, right?

Thanks

[BillP]

This reply was originally posted by L2SupportServices-Cooling on APC forums on 5/31/2017

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Hello Peter. Yes that will set one unit as the backup and one as the primary. If you want the backup unit to come on if the primary unit can not keep up with the load, make sure load assist is enabled. If you would like them to switch over, make sure run-time balance is enabled. Let us know if they are still giving you issues.

Thank you

[BillP]

This reply was originally posted by Peter on APC forums on 6/1/2017

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Thanks a lot, I will make the config changes and let you know how it goes.

Peter

[BillP]

This reply was originally posted by Peter on APC forums on 6/9/2017

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Hi,

I'm glad to say it has worked and we had a successful automatic changeover of roles between the 2 ACs.

I appreciate all your help in this matter, thanks a lot!!

Regards,

Peter

[BillP · Accepted solution]

This reply was originally posted by L2SupportServices-Cooling on APC forums on 6/9/2017

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Great to hear we got it solved. If you have any issues in the future please let us know.

Thank you