Exercise generator

[moldmkr]

I need to exercise my generator. we are hooked to shore power. Do I need to turn shore power off while running generator to put a load on generator?

[jlfbatonrg]

If your coach is like many, it has an energy management system (ems) that should switch to generator as soon as the generator comes up to speed. But the safe way is to just unplug from shore power.

[jimbo16720]

Mine doesn't have a transfer switch. There is an outlet and the plug for outside power plugs into the outlet. The outlet is hooked to the generator so if you pull the plug out the generator is disconected and the shore power feeds thru the plug.

[JMonroe]

Even those that have a transfer switch - I'd go ahead and shut the shore power off. Our last coach tripped the breaker on the gen set when I did just what you are suggesting and left the shore power connected. No damage, but annoying none the less.

[clyon51]

It depends. If you have an RV where your power cord either plugs into shore or to a recepticle in the power bay (generator), yes you would need to, to put a load on it.

Newer RVs have an automatic transfer switch which gives priority to either shore or generator. I have no idea which one your RV would use. The safest thing to do is disconnect from shore if you want to be sure to load the genny.

[amanda_h]

You are definitely going to have a transfer switch on an '08 but it's interesting to hear that the recommendation is to disconnect from shore power to exercise the generator.

By the advice we received from this forum several years ago, when we exercise the generator, we start it while plugged into shore power in order to also "exercise" the transfer switch. Is that advice still valid or is it no longer recommended to exercise the transfer switch also? We do shut down all loads when starting the generator, however.

[clyon51]

If you know your system is setup that the generator has the priority, then there's no problem leaving it plugged in.

If shore has priority, then you must unplug to load the generator. Since the OP didn't know nor the responders, it was recommened he unplug. At least that was my reasoning.

[Mr_D]

I unplug from shore power, start the gen set, and set one heat pump to cool and the other to heat, then after an hour I change the heat pumps around. Get all three "exercised" that way.

[Pepper2]

If your at a CG I would wait till you leave. No sense in everyone listening to the gen.. After you leave the CG fire up the gen. and a/c and let it exercise on your way home. If it gets too cold turn on the dash heat.

[PNWGirl]

Originally Posted by jimbo16720

Mine doesn't have a transfer switch. There is an outlet and the plug for outside power plugs into the outlet. The outlet is hooked to the generator so if you pull the plug out the generator is disconected and the shore power feeds thru the plug.

My 1990 was set up this way too, but had that changed so that it will switch over to generator on it's own and it is very nice to not have to unplug, in the pwr bay, when using generator.

Sheila

[grtharris]

When connected to shore power I would recommend either unplug the power cord or trip the breaker at the pedestal before starting the generator. On the older Magenetek ATS's used by Winnebago the generator has priority so when you start the generator the switch will transfer.
My concert is with the cord hot the switch will be switching two hot feeds and there is always a chance something could go wrong. On the ATS-5070 there are two relays one for the neutral and one for the hots that must switch. On the newer Parallax ATS-50 there are two relays one for the generator and one for shore power and they are electrically and mechanically interlock. Now that I’m looking at the schematic for the ATS-50 I do not believe the generator will override the shore power relay because it is mechanically locked out with shore power applied. The 08 Itasca Meridian has the older Magenetek ATS.
Sorry for so much info and engineering thing.

[amanda_h]

Wow, interesting conversation here. I guess we will be disconnecting from shore power whenever we turn on the generator to exercise it from now on.

We've been purposely letting the transfer switch do its thing by leaving the shore power connected when starting the gen set for as I stated before, a thread several years ago here on this forum suggested we "exercise" the transfer switch itself so it gets some use. It made sense at the time and we've been doing it ever since.

In the five years we've been doing that, the transfer switch has not failed and has worked as it should each time but I guess we've been taking unnecessary chances by doing what we've been doing. We have made it a point to make sure all loads off before starting the generator. After the transfer has been made, we then slowly start to activate appliances so that the generator will systematically be under full load as it is being exercised.

[amanda_h]

Well, you guys got DH all huffy about this. He's telling me "didn't those guys on the iRV forum say a few years ago to start the genny with the shore power connected so that the transfer switch could be "exercised? Somebody said that things should be used every so often so that they'll work as designed, didn't they?"

Well, I haven't had time to go back in the archives to search around for that specific thread but DH did look in the Parallax manual and wanted me to post what it said there:

"The ATS5070 series is designed to automatically switch the on board 120 or 240-volt appliances to generator power when the generator is activated.

No longer do you need to go outside, remove the shoreline cord from the pole and plug it into the generator receptacle. You simply start the generator and the ATS5070 will switch the loads for you."

So DH is grumpy telling me that after doing it that way for five years that now the forum is telling him to go outside and shut the breaker off before starting the generator.

*sigh* ...he'll get over it.

[clyon51]

The OP asked a general question about the subject without giving any specifics on their system and components. So they got the SAFEST generic answers.

Does DH realized there 100s of systems out there that does the same thing but operated differently?

Had the OP been more specific and said they had a Parallax ATS5370. they would have received the same answer he did 5 years ago. If he's still huffy, tell him to drink 3 martinis and check with us tomorrow.

[amanda_h]

Originally Posted by clyon51

The OP asked a general question about the subject without giving any specifics on their system and components. So they got the SAFEST generic answers.

Does DH realized there 100s of systems out there that does the same thing but operated differently?

Had the OP been more specific and said they had a Parallax ATS5370. they would have received the same answer he did 5 years ago. If he's still huffy, tell him to drink 3 martinis and check with us tomorrow.

Thanks, John! I sort of overreacted too so both DH and I went back and re-read this thread again and you're right.

We are going to continue to leave the shore power connected when we exercise the generator as we also want to exercise the transfer switch also.

The way we usually do it is to 1) shut down all loads in the coach, 2) start the generator, 3) wait for the transfer to take place --usually within a minute, 4) once the generator is powering the coach, slowly start bringing things onboard such as turning on the water heater, a/c, space heater, etc. until we know that a good solid load is on the generator, 5) let run for at least an hour, 5) start shutting off appliances so that essentially all load is off the generator, 6) shut generator off, 7) let transfer switch do its thing so coach goes back into shore power.

Does this sound okay? We do not touch the power pedestal at all during this process ...we leave the the power plugged in and live. We've been doing it this way for five years at least once a month when we are stationary without any problems so far.

[clyon51]

amanda, your plan sounds perfect and must be since you've never had a problem!