Camper Breaker NOT Tripping

[IchLiebeBier]

Hi all,
I need some electrical schooling here to understand what is going on to make sure I'm not harming anything. Any help would be appreciated.

I have the trailer plugged into the 50 amp pedestal using a 30 amp dog bone. The power line goes like this: pedestal -> dog bone -> Hughes Autoformer -> Hughes Power Watchdog -> Camper. Camper is 30 amp. First time using the Power Watchdog.

The Power Watchdog shuts down the power if I exceed 30 amps. I tested it today and saw a rise to about 35 amps on the PWD app before it tripped.

My question is this: why isn't the camper circuit tripping if it exceeded 30 amps? And will that cause damage in the long run to either the camper or the PWD?

Thanks.

[Thomas ho]

because the watchdog is before trailer breaker like a Gfi.

[Reverse_snowbird]

My question would be.... why are you not concerned that the PWD waits til 35 amps to trip? Isn't that supposed to protect your rig from amps over 30?

[IchLiebeBier]

Originally Posted by Thomas ho

because the watchdog is before trailer breaker like a Gfi.

But the camper circuit breaker is between it and the stuff in the camper.

[IchLiebeBier]

Originally Posted by Reverse_snowbird

My question would be.... why are you not concerned that the PWD waits til 35 amps to trip? Isn't that supposed to protect your rig from amps over 30?

That was part of my question. I thought it was more implied than that.

[CedarCreekWoody]

Most breakers are not highly accurate instruments that immediately trip at their rated capacity. I've seen them take a bit of time above rated capacity before they trip. I've also seen the opposite where they trip early.

[Flybob]

Most likely the reason is that the Power watchdog is an electrical device with an instantaneous trigger point, while the breaker is a heat activated mechanical device that is not as fast acting. If you remove the watchdog and run the same load it will most likely trip the breaker.

[IchLiebeBier]

Makes sense. Thanks all.

[Larry-NC]

Originally Posted by Flybob

Most likely the reason is that the Power watchdog is an electrical device with an instantaneous trigger point, while the breaker is a heat activated mechanical device that is not as fast acting. If you remove the watchdog and run the same load it will most likely trip the breaker.

Flybob is right! In the summer of 1967 I had a co-op job (called intern now) as an electrical engineer consultant to architectural firms doing large building designs. I read a bunch of breaker specifications.

A typical breaker spec would read something like

• Time to trip at 1000% overcurrent: 25-200 milliseconds
• Time to trip at 120% overcurrent 20-60 minutes.

These aren't exact numbers, just something similar to how circuit breakers are specified.

[campers302]

Originally Posted by IchLiebeBier

Makes sense. Thanks all.

I am no electrician. But just because the trailer is receiving a little more to the breakers would not make them trip until you put a draw on the breaker.
Maybe the electricians in the group could verify this for me.
And you inline will not pass through more than the 30 amps so it breaks first.

[pmurph991]

Being an electrician for 30+ years, I can say that breakers are designed to handle an over current situation for a short period of time. Your Watchdog is most likely designed with tighter tolerances.

[IchLiebeBier]

Good info. Learned something today. Thanks.

[tgold]

A breaker trips on heat caused by over amp draw or short circuit. A good breaker and cool weather will allow a 30 amp breaker to draw 35 amps for a while. No way to determine exactly how long because it depends on name brand of breaker and amp draw and ambient temperatures and a lot of other conditions.
Your trailer wiring should handle the amp draw without harming the wires. The wiring is probably rated for 35 amps in the trailer anyway. Romex is probably what is in the trailer and even though number ten romex is rated for 30 amps the inner insulation is probably thhn or twhn which used as a single conductor in conduit is rated for 35 amps when calculating the derate on the wire. All this to say no worries. you also have individual circuit breaker protection with your trailer panel. You are more likely to have a surge from the pedestal you plug into hence the protection you are using to prevent that.

[ependydad]

I know that I have read on here that the Progressive Industries amp meter reads higher than the actual amps being used (like you take 1/3 off of the total displayed). Is it possible that your Watchdog is the same?

[lbrjet]

I have never read that and mine is very accurate.

Originally Posted by ependydad

I know that I have read on here that the Progressive Industries amp meter reads higher than the actual amps being used (like you take 1/3 off of the total displayed). Is it possible that your Watchdog is the same?

[ependydad]

Originally Posted by lbrjet

I have never read that and mine is very accurate.

Here it is. Hondaman reported that his was off and that PI indicated it was just an estimate:
https://www.forestriverforums.com/fo...-a-164111.html