Dimension Output Breaker???

[dengraham]

Okay, I'm hooked up to 50 AMP pole, I overload a circuit (micowave, tv, satelite, dvd, coffee pot, oven all at the same time. But, instead of a circuit breaker triping, the output breaker on the Dimension Inverter trips. Did tis twice??? Shuts down one side of the coach?? I need help understanding what is happening. Thanks in advance.

[MrTransistor]

Hello Dennis,

The explanation is here.

http://www.winnebagoind.com/diagram/...ire_158650.pdf

Even though you are connected to a 50 Amp. service, most all the outlets are connected after the inverter. All the loads that tripped the breaker are on one outlet or another and even though the inverter was in bypass the current still had to pass through the inverter circuit breaker. The AC, Washer/Dryer, Dishwasher, Refrigerator, and Engine heater are tied in before the inverter so they did not contribute to the tripped breaker and would have continued to operate.

So, you can get 50 Amps. plus 50 Amps. but not all of the 50 from the outlets, only 30.

[SteveG]

Hm... Dennis, are you saying that the 30 amp breaker that is located on the face of the Dimensions unit opened? And that neither the main or microwave circuit breaker on the Inverter Breaker Panel located on my unit at the end of the bed did not open?

Mark are you saying that the Inverter breaker panel cannot draw more then 30 amps because its main breaker is rated at 30 amps? So the design assumption is that even though the four 15 amps circuit breakers total 45 amps it is not likely that all the circuits will be drawing power at the same time? And that even though the individual 15 amp circuit might not exceed 15 amps if all four were pulling 15 amps the 30 amp main located in the inverter panel would open when the amperage exceeded 30 amps.

On my Dimensions unit the output breaker is 30 amps. According to the Dimensions book this CB trips to protect the Dimensions unit from an output short circuit or overload.

It is also interesting that when the Inverter is in the bypass mode (allowing normal 110VAC power to pass through the inverter to provide power to the house circuits)and the Dimensions 30 amp circuit breaker opens, I can not find anything in the Dimensions book that indicates there will be a warning light or error message that the Dimensions CB tripped. Their troubleshooting procedure does remind that the circuit breaker needs to be checked when power is lost.

Dennis, if your response is that the Dimensions 30 amp CB tripped before the 30 amp Inverter panel breaker then it would be interesting to give Dimensions a call to see if they can explain why it did that.

Our 2004 36G Journey wiring diagram is pretty close to the one Mark provided.

Thanks for posting this problem as it is helpful to study and understand how things work.

[MrTransistor]

Hello Steve & Dennis,

Correct on all counts. It is very common practice to use what would seem to be an undersized breaker to in turn feed several other breakers. As in a house panel, it may be a 100 Amp. service and have a 100 Amp. main breaker but if you were to add up all the 15, 20, and 30 Amp. breakers installed you could have a total of much more than 200 Amps.

The reason this is so is because of a thing called ˜simultaneity' factor, that takes into account that not all circuits will be loaded to their maximum at the same time. There are charts that have been put together for just about every conceivable scenario. From multi-room X-Ray departments to manufacturing plants to houses. These same charts are used to size transformers and wiring that feed areas of houses.

As to which breaker tripped, it could just as easily have been the breaker that feeds the inverter. All breakers are designed and usually guaranteed to hold their rated current 100% or the time. But above that, say at 120% current, they could hold for 10 seconds or 10 minutes and still be in spec. Breakers also use a thermal device as well as electro magnetic to sense current so the ambient temperature affects when it will trip. We are connected to a 30 Amp. service and when it's cold, I have seen momentary currents as high as 42 Amps. for several seconds without the breaker tripping. In the heat of the summer, it will usually trip right away with as little as 32 Amps.

The inverters have a contactor inside that automatically switchs from the incoming line to the output if it senses line voltage and if not, to inverter output. So it doesn't mater whether the circuit breaker is located on the input side or output side of the inverter, it still has to protect either the inverter or the contactor's contacts which are usually rated for 30 Amps. To the user, it doesn't mater what part of the circuit the breaker is inserted into, just that there is a breaker on the inverter. It is usually on the output side since the input side should already be protected by an external 30 Amp. source.

[dengraham]

Thank you Mr Transistor. You are right on and extremely helpful. As Steve suggests it does seem funny to have to run outside and push the button on the inverter instead of flipping a circuit breaker but I guess it was the first place to notice the problem. Thank you very much for your clear and consise explanation. I think the little ceramic heater was the "icing on the cake" that pulled it over, er out!
Safe travels to all.

[MrTransistor]

Thank you, I'm glad to help.

[kscouple52]

will repeated tripping of the output breaker case it to become weaker and weaker, seems like i cant turn on anything (microwave/convection, or heater) without it tripping.