Hooking up to power

[MSHappyCampers]

Hi ! Welcome to IRV2! We're sure glad you joined the gang!

Congrats on the new rig! I agree with what most others have said. I would turn off the genny before connecting to shore power. Also, turn off heavy loads such as A/C's, microwave, etc.

Good luck, happy trails, and God bless!

[A Traveler]

Originally Posted by ThePowells

...I usually leave mine on when connecting since Kelly is usually working and I am trying to leave everything running for her.

Here’s another reason to leave the inverter on all the time. If your inverter is on, shutting off the generator won’t shut off anything in the house except the air conditioning. When the AC power from the generator stops, the inverter immediately takes up the load and nothing shuts off.

When the AC shore power comes on, the air conditioning comes back on and you’re back where you want to be.

I always shut down the generator first. Why burden the transfer switch by transferring power with a high amp draw? With the generator off, the transfer switch goes over with almost no amp draw through the contacts.

[Beau388]

All electric motors produce a back electromotive force (EMF). That is why they don't over-speed then the load is removed and why they slow down so little when the load is increased. When the relay points open, there is a very strong magnetic field in every electric motor that collapses and is exactly opposite to the incoming current. It works just like an ignition coil in a gasoline engine This current is going to try and keep the circuit going. The arc produced will not usually be over 50 volts but can be many amps severely pitting the relays points. Resistive loads don't matter when you open the transfer relay in the transfer switch but inductive loads do. So, no electric motors running when you transfer power through a relay unless you have a really big capacitor across the points to absorb the arc.

[SuperGewl]

I'm going to say it again.
First open the breakers on the Camp Ground Pedestal.
Second, shut down your A/C's.
Third, Shut Down the generator after a short cool down period, 2-3 minuets.
Fourth, Plug in you shore Power cable and then energize the breakers at the pedestal. ( hopefully you have a Surge Protector installed. If using a portable one then you could have plugged it in right after opening the circuit breakers then you could have closed the breakers to allow it cycle thru its pedestal check)
Fifth once the Surge protector has completed its safety checks if all is good start the A/Cs back up.

[AKIQPilot]

Originally Posted by SuperGewl

I'm going to say it again.
First open the breakers on the Camp Ground Pedestal.
Second, shut down your A/C's.
Third, Shut Down the generator after a short cool down period, 2-3 minuets.
Fourth, Plug in you shore Power cable and then energize the breakers at the pedestal. ( hopefully you have a Surge Protector installed. If using a portable one then you could have plugged it in right after opening the circuit breakers then you could have closed the breakers to allow it cycle thru its pedestal check)
Fifth once the Surge protector has completed its safety checks if all is good start the A/Cs back up.

Exactly. Anything else is asking for trouble.

[TLGPE]

I'm going to be the contrarian, and agree with Twinboat. Our inverter runs almost all the time to keep the house appliances working. The power transitions are seamless.

We run the genney when driving to keep the AC units going. When we reach a park, we first make sure the breaker is off at the post and plug in the cable and turn on the breaker. The surge protector checks the power condition, and if it's good allows power to be available to the house. This takes about a minute and a half. THEN we stop the generator.

That process is also seamless. The AC units never miss a beat, the lights don't flicker; it truly is seamless.

We have done this for six years. The equipment is well designed to handle all this and it works well. We see no reason to mess around with it.

YMMV, but really, it's designed to work this way.

Tom

[D K]

I worked as a captain/engineer on superyachts for many years which are essentially RVs on water..

if the vessel is equipped with seamless power transfer, then you don't have much to worry about and would be a good idea to practice that feature just to make sure it works and settle the argument once and for all.

If it doesn't have seamless PT, then you should still be ok to make a hot transfer because there is a breaker in the system that will open in case of reverse power or anything in that nature. It would be a good idea to make sure that breaker works as well.
That said, it's always a good idea to make a manual transfer with the load as small as possible, so turn off the big stuff.

D

[tropical36]

Originally Posted by MacySun

I am a new owner of a '15 Forest River 351 MH. I haven't taken my inaugural trip. I'm concerned about my initial plug in to power. I was told that this MH is equipped so that I don't have to shut down the generator for the transition from generator to 110 power. Does that sound correct? What should I look for and how can I make sure.
Concerned & new in Tequesta.
PA

This is correct and won't make a difference. The genset is default, so no transfer will take place. I would however, turn off heavy loads, like the ac's before shutting it down. Once it automatically transfers over to shore power, you can turn them back on. Don't like the idea of disappearing voltage taking place with the ac's. I have no problem with just turning off the genset breaker abruptly, but why bother with doing that........

[ThePowells]

Why do I feel like I just got a beat down???

[cavie]

I wish all you guys with these rolling yachts would learn the difference between a surge protector and an EMS. Surge protectors protect from high voltage spikes and nothing more. An EMS will protect from hight and low voltages and turn off the power on and off to protect your electronics. A surge protector doesn't. These two pieces of equipment are as different as salt and pepper. Please learn to use the correct language so the newbies can learn correctly. I read all the time about newbies buying the wrong thing because they read about it on a forum. When you know the difference and see it use incorrectly please explain it so everybody learns.

[mortensen5]

While traveling, we tried to start generator to run A/C unit. Gen started, but no 120V to A/C. When we got to the park, I plugged into shore power to run the A/C. At the Progressive Dynamics PD52(P) transfer switch, my voltmeter showed ~30VAC from gen N to Hot1 or Hot 2 -- with gen not running. Any ideas where the 30 volts came from?

(The shore source voltage detector is supposed to sense 16 volts whenever shore power is detected; but why do I have 30 volts?)

I started the gen, and the green LED in the transfer switch indicated presence of >90V, so, after a 20-second delay, it switched to gen input. But now there was 140+ VAC between the generator N and each hot leg! And the contractor just chattered and wouldn't close, so I turned off gen.

No breakers tripped.

The generator and transfer switch always work perfectly when I exercise the generator each month...

Any ideas what's wrong?

[ScotS]

Here's my two cents ...


I have found several manufacturers of AUTO transfer switches.


https://www.progressivedyn.com/rv/au...sfer-switches/


https://www.escousa.net/technical-do...sfer-switches/


PMTS Series - PowerMax Converters


They all consist of 2 power relays and a time delay for generator start, and they all will transfer shore power and generator sources automatically. None of these contain an auto synchronization circuit to switch only when the power is "in phase", meaning the relays will only operate when the generator and shore power are at the same exact point in the voltage cycle. This is important to keep the switch over "clean" and without a "voltage spike or dip". Most modern equipment and motors can handle this "bump" in voltage for a single cycle, but when this occurs repeatedly over many cycles, bad things can happen. If the relays are operating a "Simultaneous Break Make" operation without synchronization, this voltage "bump" should only happen during a single cycle, or if the relays are operating a "Break Before Make" operation, temporarily disconnecting the RV from both shore and generator power before connecting to the desired power source, this is usually very fast and just for a few cycles. Again, modern equipment can usually handle this extremely short disruption in power, think of a power dip during a storm.


Getting the make and part number off of your particular Transfer Switch and looking up the manufacturer data will give you more insight to their switching operation, recommendations, and requirements.


... well, maybe a nickels worth

[Props2]

You would think the price we pay for these rigs,they could throw in some sync check relays for the transfer switch. I know the relays aren't cheap, but still.
With that being said,the transfer switch is rated for full load transfers other wise what good are they. When I was commissioning electrical equipment for the large data centers,we load them 100 percent usually for 4 hours or more and make transfers routinely. These of course are monitored by data loggers and these were the least of troubled equipment. Make before break transfers require same source energy if it has no sync relays, don't even try it without.