Another Surge Protector Question

[KDHfan]

I received my Progressive Industries EMS-PT30C today. I had an assumption that I think now is a good time to verify...
There have been a few times I've arrived at a campground only to find the 30amp service plug a little questionable and/or "used"... So I pull out my 50-to-30amp converter and plug into the 50amp service.
So my first question... Is there any advantage/disadvantage to doing this?
The question on my assumption... Will I be able to plug my 50-to-30amp converter into the pedestal, then plug my EMS into the converter, and finally my 30amp power cord into the EMS? Disadvantages/concerns to doing this?

[davel1971]

no reason you can't. You can't "force" more power into RV. Amps are "drawn", and you can't exceed the breaker in the RV so no worries

[MillerTime]

Advantage of having all the 30 amps available at your breaker, instead of less from a weak cg 30amp breaker plus other losses from conections and cords (although the latter two should be minimal).
I've never to this day used a 30 amp plug, even when I had a 30 amp trailer I always used the 50 amp service and a dog bone.
(And I rarely had trailer breaker issues on my 30amp trailer, unless I tried to run the ac, microwave, tv, and h2o heater all at the same time)

Millertime- Sabre Handler

[MillerTime]

Oh and on 50 you wont have to worry quite as much that someone hooked it up wrong . Cause its wired the same as what most 240v appliances use.
A lot of people wire up 30 amp 3 prongs wrong.

Millertime- Sabre Handler

[dave961]

So.. you don't need anything to 'step down' from 50 to 30? Just get a 'dogbone' with a 50a male on one end and a 30a female on the other?

[fonzie]

Originally Posted by dave961

So.. you don't need anything to 'step down' from 50 to 30? Just get a 'dogbone' with a 50a male on one end and a 30a female on the other?

Correct....

30 Amp RV Female to 50 Amp 125/250V RV Male Pigtail Adapter with Pull Handles - Furrion IP3154R-SB - Electrical Adapters - Camping World

[MillerTime]

Originally Posted by dave961

So.. you don't need anything to 'step down' from 50 to 30? Just get a 'dogbone' with a 50a male on one end and a 30a female on the other?

Yep just like the dog bone im the middle of this pic

You can get them at Walmart for about $16 - 17

Millertime- Sabre Handler

[KDHfan]

Originally Posted by MillerTime

Yep just like the dog bone im the middle of this pic

You can get them at Walmart for about $16 - 17

Millertime- Sabre Handler

Awesome... The exact set-up I have.

[Herk7769]

For completeness only:

There is are potential situations were using the 50 amp outlet via pigtail on a 30 amp camper can get you into trouble.

While your camper's main breaker "should" prevent you from pulling more than 30 amps into the camper (because it is supposed to open at 30), it takes a time for the breaker to heat up enough to open. That amount of time is dependent on the degree of overload.

For example, a 30 amp breaker should open almost immediately when a dead short occurs (a few hundreds of amps instant); but an overload of an amp or three could take a long time (several minutes even). Same with the pedestal breaker.

In the short run, this is a "good thing" because it allows "micro-overloads" (say from starting the compressor on the air conditioner while using other stuff in the camper) from tripping the breaker all the time.

When it becomes an issue, is when the power panel is "seeing" a full load of 30 amps and your wiring, sockets, cord(s), and plug (all rated for 30 amps) are "seeing" significantly more.

This can easily happen with:

1) Extension cords. Folks with 30 amp campers buy 30 amp extension cords to extend their OEM cord's reach when needed. This is not a problem on a 30 amp outlet because the amperage used to push its way to the camper "can not" exceed the 30 amp breaker on the pedestal and will open first protecting your cords and connections.

However if you use a "dogbone" adapter on the pedestal's 50 amp socket, then connect your power cord(s); the cords and connections are not protected and they may be operating continuously in an overloaded condition. This can result in cord damage, connection damage from heat and arcing inside the connector.

2) You use a 30 amp rated auto-transformer. Auto-transformers work by using a small amount of incoming current to boost low voltage at the pedestal (various causes) to near normal to prevent damage to the camper's inductive items (air conditioner, fan motor, microwave) when low voltage is encountered.

Since auto-transformers are installed before the power center and have their own internal current limiters, the wiring between the auto-transformer and the 50 amp outlet will be unprotected from continuous small degree (potentially large) overload.

[ChooChooMan74]

Add one note to what Herk said. I was working on my friends recently purchased 2000 Coleman Pup. I had to pull apart his power center, due to no 12 volts (converter fried). Comes to find out, his power center/converter, which is not made any longer, did NOT have a main breaker. He had a 20 amp breaker for his AC and a 15 amp for his converter and plugs. If he uses an adapter, he could pull 35 amps. On a setup like this, I would not recommend a 50 to 30.

I myself carry one, and use it when I can.

[Herk7769]

Originally Posted by ChooChooMan74

Add one note to what Herk said. I was working on my friends recently purchased 2000 Coleman Pup. I had to pull apart his power center, due to no 12 volts (converter fried). Comes to find out, his power center/converter, which is not made any longer, did NOT have a main breaker. He had a 20 amp breaker for his AC and a 15 amp for his converter and plugs. If he uses an adapter, he could pull 35 amps. On a setup like this, I would not recommend a 50 to 30.

I myself carry one, and use it when I can.

Are you sure the 20 amp breaker was not his "main"?

Pup's sometimes use the 20 amp as the main and that is where the shore power connection is attached to feed the 15 amp circuit(s).

[ChooChooMan74]

Originally Posted by Herk7769

Are you sure the 20 amp breaker was not his "main"?

Pup's sometimes use the 20 amp as the main and that is where the shore power connection is attached to feed the 15 amp circuit(s).

100% sure. I should have taken pictures. But the 30 amp cord went right to the bus bar. He had a blank on the left side where another circuit could be added and a dual 20amp/15amp breaker. 15 amp side went to his converter and plugs. The 20 amp side went to a 20 amp plug where his AC would plug into.

Now, thinking about it, next time I work on it, I may make it safer and add a 30 amp circuit breaker to the blank, and wire the cord to that breaker.

EDIT:

This picture is not his in his camper, but I found online from the info I had in TXT messages. It is a Centurion CS 2000 and this is exactly how it was wired.

[Herk7769]

<shakes head in disgust>

[KDHfan]

Herk... So if I'm reading correctly, you're saying that a set-up of... 50amp-to-30amp pigtail ---> Then my surge protector ---> Then my RV power cord going directly to the camper, should be ok. But if I throw in a 25', 30amp extension cord into the mix, that it could lead to problems?

[Herk7769]

Originally Posted by KDHfan

Herk... So if I'm reading correctly, you're saying that a set-up of... 50amp-to-30amp pigtail ---> Then my surge protector ---> Then my RV power cord going directly to the camper, should be ok. But if I throw in a 25', 30amp extension cord into the mix, that it could lead to problems?

What I am saying is that your equipment is rated to 30 amps.

Connecting to a source that won't complain until it hits 50 amps leads you into "no man's land" between the source and your first 30 amp protection.

If you hang your power protector right after the pigtail, you should be OK since the power protector should have a 30 amp breaker in it.

If it does not, then everything between the 50 amp source and the first 30 amp current limiter could be subject to a "potential" current higher than 30 amps without anything tripping.

As an example, say you are using a 25 foot 30 amp extension cord to connect to your 50 amp pigtail and the junction between the camper cord and extension is laying in the grass. Then it rains and the junction gets wet. A high resistance short occurs at the pins due to the water.

The current being carried by the extension cord and pigtail could easily exceed 30 amps without the camper's main tripping (because as far as it is concerned the amperage is less than 30) and as long as the resistance short draws less than 50 amps, power will continue to flow.

At the junction, the temperature will increase until it melts the junction (causing a full short) or until it ruins the cord.

Just saying that "routinely" using the 50 amp socket via pigtail carries risks that you might not be aware of. Now, if the choice is taking that risk or no power; then "roll dem bones" and plug in. I certainly would.

Just saying you need to keep an eye on things and feel the wires for heat every once in a while. Might save you from replacing an expensive cord set.

[KDHfan]

Gotcha. Thanks.
My initial thought is if I pull in and there's something wrong, or goes wrong, with the 30amp, I could just jump over and try the 50amp before asking to move sites.

[Herk7769]

Originally Posted by KDHfan

Gotcha. Thanks.
My initial thought is if I pull in and there's something wrong, or goes wrong, with the 30amp, I could just jump over and try the 50amp before asking to move sites.

Yep, I do it all the time. I damaged my socket at the camper by not watching out for the overload when I used the 50 amp socket a a campground experiencing low voltage.

I had my Franks Auto-transformer boosting away and my AC was the only one running. When we broke camp, I had trouble unplugging my cord from the camper and noticed the tips of my socket blades were burned. Now there is an incoming ammeter where I only had a volt meter previously.

[BamaBob]

Originally Posted by KDHfan

I received my Progressive Industries EMS-PT30C today. I had an assumption that I think now is a good time to verify...
There have been a few times I've arrived at a campground only to find the 30amp service plug a little questionable and/or "used"... So I pull out my 50-to-30amp converter and plug into the 50amp service.
So my first question... Is there any advantage/disadvantage to doing this?
The question on my assumption... Will I be able to plug my 50-to-30amp converter into the pedestal, then plug my EMS into the converter, and finally my 30amp power cord into the EMS? Disadvantages/concerns to doing this?

I actually called Progressive about this - I was a "Camp Manager" on a somewhat sketchy RV camp the non-profit I belong to was using. I was concerned about the power being provided at the plugs. We had both 50 (me) and 30(some) and even 110V hookups using the CG power. Progressive told me that my portable 50AMP unit would check all three using adapter plugs. Worked great!! AND I was the CG hero for making sure all the power was safe for folks (who did not have the Progressive Power Manager godliness unit )

[Cypressloser]

Originally Posted by Herk7769

Yep, I do it all the time. I damaged my socket at the camper by not watching out for the overload when I used the 50 amp socket a a campground experiencing low voltage.

I had my Franks Auto-transformer boosting away and my AC was the only one running. When we broke camp, I had trouble unplugging my cord from the camper and noticed the tips of my socket blades were burned. Now there is an incoming ammeter where I only had a volt meter previously.

Oh boy, you're making me curious (jealous).
It looks like your trailer is wired for 30 Amp, for a 50 Amp setup would you need two separate Volt/Amp meters?

[Herk7769]

Originally Posted by Cypressloser

Oh boy, you're making me curious (jealous).
It looks like your trailer is wired for 30 Amp, for a 50 Amp setup would you need two separate Volt/Amp meters?

Yes. one for each leg. The 50 amp Franks Unit is actually a pair of Auto-transformers in one box. Each leg is boosted, or not, independently.