done

What voltage does your gen put out?

How much voltage drop are you seeing when A/C Compressor starts?

Voltage below 108VAC will cause damage to inductive loads ..motors/transformers

While mine has had issues with my under powered generator I doubt you would have any trouble with a 4000+ watt generator.

tmartin000 wrote:
Thanks gents.

I am not going to put the EMS-HW30C after the generator. I've decided to wire it only protecting the input from the street or pedestal only.

If they had published its response time, this question would have been moot.

So if it wasn't instant it wouldn't protect your appliances. It's a great unit. I have the 50amp version.

Jerry Parr

done

If I understand correctly you're asking what the EMS-HW30C's shut off response time is? If so, I'd say based on my own unit that's it's "instant"


And that answer should suffice I would hope.

I'll never forget a public "figure" answering a question about his misconduct with
"It depends on the meaning of the word 'is'"

I also just have mine on the shore power side. The unit would have to be wired in after the transfer switch to monitor gen.

I have my unit plugged into the pedestal so it's not affected by the Gen.
Wire yours in so only monitor shore power.
They are made to primarily monitor shore power.

tmartin000 wrote:
Here is the question.....How fast is it? I really don't want my A/C causing the genet's output to stop overtime the compressor kicks in.

If I understand correctly you're asking what the EMS-HW30C's shut off response time is? :@ If so, I'd say based on my own unit that's it's "instant" ... yeah I know, not scientific but once voltage crosses either the low or high voltage threshold it shuts off "instantly". If the power source was my genset rather than shore power the moment the A/C compressor kicked on voltage drop would cause the relay inside the EMS to chatter ... solution is to remove the unit from the system when running on genset, ergo the reason I installed mine using 30 amp connectors. As far as surge protection is concerned the unit is spec to react in < 1 nanosecond.

As you're probably aware threshold voltages for the EMS-HW30C are 104 vac low and 132 vac high but that assumes the unit has been correctly calibrated. Mine wasn't but rather was reading almost 2 volts high and the result was it wouldn't shut off at 104 vac but closer to 102 vac ... fortunately the hard wire HW30C, unlike the sealed portable unit, can easily be re-calibrated provided you have a meter of known calibration.

Ha. You are right about calling them. :)

I tried to set the genset to vary VERY little with the compressor startup. But getting a near perfect voltage drop is darn near impossible....

Im going to move forward and just protect the wires from the pedestal to the input to the Camper. I have to admit, its not the first time Ive tried to over-engineer a project.

Thanks for the help focussing.

tmartin000 wrote:

So, calling may be the only way to get a real answer....

How about TRYING it a few times to see what happens ???

Or am I missing something here ?

Seems to me like the "tweaks" you have already done should have shown up a problem already.......if there is one.

Oh, and calling them probably won't get you any better answers either.