UTS6H Load Transfer Question

[Anonymous user]

Hello,

I was wondering if I could get a little more information about the Load Transfer feature of the UTS6H. The manual only mentions this feature briefly as an option in the UTS Configurable Features table list but does not go into any details. I am trying to decide if this feature would be worth getting a UPS.

First I want to say that I do not plan to use the uninterruptible feature of the UTS because the loads that I would want to be uninterruptible are on branch circuits with many other types of loads and do not want this branch circuit to be powered from Circuit 1 all the time as indicated in the manual.

However I can see the usefulness of using a UPS as a temporary load share if needed. So how does this work? I'm assuming the "Either" setting would have to be selected in the Circuits Setup? What happens to these selected loads when utility power fails? Will the UPS power these loads immediately or would the generator need to be started before the UPS can be used?

[BillP]

hello, personally i am a little rusty on UTS questions so I asked someone who deals with it more frequently. here are some questions/comments:

is it possible you are confusing load shed and load transfer? The transfer is just referring to the UTS and how it will transfer the power from utility to UPS to generator. If you doesn't want to have uninterruptible circuits and don't want to have the generator auto start, then a UPS is not needed. The load shedding would be more of turning off and on non essential circuits if it looks like the load may overload the generator (one of the reasons you have to set the generator capacity in the UTS).

let us know if we misunderstood or if you have further questions.

[Anonymous user]

Thanks for replying.. I think you misunderstood. I understand that "Load Shed" is shutting down a circuit. On page 3 of the Operation Manual currently available on the APC site, "Load Transfer" is listed, along with Load Shed & Time Management, as a feature under the UTS Configurable Features table stating, "Provides automatic transfer of select loads between a generator and a UPS". I'm assuming this means the UTS can switch a load (with the exception of circuit1) from the generator to a UPS if it determines the generator is close to overload in order to minimize power interruptions. Also assuming that selecting "Either" in the Circuit Setup will enable this behavior but I'm not positive because there is no other mention of "Load Transfer" anywhere else in the manual.

My question is what happens to a circuit programmed as "Either", not "Uninterruptable" (meaning, can be powered from a generator or UPS) when utility power fails. My generator is manual so will not be available when utility power fails until I set it up. Will that circuit, programmed as "Either", be switched to a UPS (with the understanding there might be a power interruption) or will this type of load transfer only occur if a generator is running but close to overload, when a Load Shed might occur?

The owner's manual is very thorough and well written but information is sparse regarding this feature.

[Anonymous user]

Thanks again for the reply. 🙂 This is a very cool transfer switch and I hope it's a big seller for APC. It's only down side that I can see might be its size, but this is not an issue for my installation. Thanks again for answering my question.

[BillP]

ok, did some more research with some folks here.

You are correct in that setting the circuit to either will allow the UTS to auto select the source for that circuit, which would aide the unit during Adaptive Load Management. In a case where the generator is unable to provide adequate power to the load, the UTS can switch one circuit to UPS instead of having to "delay" it or turn that circuit off.

Now, the only way the circuit will receive power while the UTS is switching between utility and generator is if the circuit is set to Uninterruptable. The either or UPS setting will not do this.

[Anonymous user]

Thanks again for the reply. 🙂 This is a very cool transfer switch and I hope it's a big seller for APC. It's only down side that I can see might be its size, but this is not an issue for my installation. Thanks again for answering my question.

[Anonymous user · Accepted solution]

Thanks again for the reply. 🙂 This is a very cool transfer switch and I hope it's a big seller for APC. It's only down side that I can see might be its size, but this is not an issue for my installation. Thanks again for answering my question.