Testing a breaker

Steve S · 07-01-2014, 04:43 PM

My question is can a breaker be tested to see if it's good or bad?
I've had the ac running a few times, the first time about 5 hrs a day for a week and no problems.
Then the breaker started to trip within 2 hrs. Now it seems to want to trip every 15 mins.
The ac is working properly, no weird noises and it cycles properly.
Is it pretty common for these to wear out?

alexsbuddy · 07-01-2014, 05:06 PM

Yes, here is a youtube link on how to do the test:

http://www.youtube.com/watch?v=ClF_ibrHYAg

Breaker failure is not common, but certainly possible. But a breaker usually either works or does not work. Your issue sounds intermittent which leads me to believe it is something else. I would also test to make sure the unit is drawing the correct amperage. Excessive amp draw is a common cause of breaker tripping. I am not a hvac tech, but dirty coils, insufficient air intake, and other issues can impact the operation of the unit which in turn leads to a higher than normal amp draw which then trips the breaker. Good luck.

alexsbuddy · 07-01-2014, 05:20 PM

Here are some troubleshooting ideas for your problem:

Shorted component or wiring
Locked-up motor or compressor
Weak or ruptured capacitor
Loose electrical connection
Loose breaker
Bad breaker
Over-amping due to a mechanical problem
Under-sized breaker or wire
Weak compressor
Low voltage

Hope this helps.

Steve S · 07-01-2014, 05:51 PM

Wow you guys scare me sometimes

It's 20 amp glued to the main breaker. Does this have to come from the RV place or can I get it at the box stores?
I did post about maintenance on the ac awhile back and followed everything that was posted and everything looked fine

alexsbuddy · 07-01-2014, 06:24 PM

When is this issue occurring (connected to shore line, at different sites, or just at home)? When the issue occurs does the breaker feel hot? Slightly warm is normal, but hot means it is drawing too many amps which is not good and indicates an operating issue.

Some big box home improvement stores do carry some RV electrical parts, but are limited to universal use items. I would contact the service department of your dealer and ask them what they recommend. I am not sure if the same applies to RVs, but, in most cases, breakers for home use must be matched to the brand/style of service panel that you have.

Steve S · 07-01-2014, 07:12 PM

I'm connected at home through 30 amp. The breaker barely gets warm just before it kicks off.

**JRTJH** · 07-01-2014, 07:37 PM

This link is to the installation manual for the WFCO 8900 power distribution center (55Amp)

http://www.wfcoelectronics.com/Image...erDocs/9-3.pdf

On the second page is a list of "acceptable circuit breakers" Below that list is this statement: "A replacement or additional circuit breaker shall be of the same manufacturer, type designation, and equal or greater interrupting rating, not to exceed 30 A
- "Short-Circuit-Current” rating for the breaker should be 10,000 A"

So, no matter what's available at the "big box store" You will need to open your distribution center, find out what is installed and use the same brand, and type of circuit breaker that's already installed, so you do need to unplug your RV, take off the front panel of your power center and remove the breaker to see what it is and then get an identical replacement for it.

Steve S · 07-01-2014, 07:54 PM

Thanks John, I'm thinking that I'll take the breaker to the dealer as that's what they do for a living and have always given great advice. They even saved me from spending 400 the last time I was in there

alexsbuddy · 07-02-2014, 02:46 AM

While you are at it, I would check the breaker in your home service panel that supplies service to your 30amp connection. The problem may be associated with your 30amp service rather than your RV.

Steve S · 07-02-2014, 05:20 AM

Quote:

Originally Posted by alexsbuddy

While you are at it, I would check the breaker in your home service panel that supplies service to your 30amp connection. The problem may be associated with your 30amp service rather than your RV.

I just replaced that breaker a few weeks ago as it was causing a few probs.

B&T · 07-02-2014, 07:42 AM

just a shot in the dark;

Have you checked your post plug for corrosion? A high resistance there(or anywhere in the line) would cause an extra voltage drop which would cause the Air Conditioner to pull more amps than normal.

Steve S · 07-02-2014, 09:11 AM

Quote:

Originally Posted by B&T

just a shot in the dark;

Have you checked your post plug for corrosion? A high resistance there(or anywhere in the line) would cause an extra voltage drop which would cause the Air Conditioner to pull more amps than normal.

I'll check but I doubt it as it's all brand new.
So it's a pretty mild day and I turn the ac on @ 7 am, back @ 10 am and everything is still working fine.
It was tripping yesterday when it was cooking in here. Could the heat be causing the breaker to trip like as in the ac unit is too hot to run?

**hankpage** · 07-02-2014, 10:52 AM

Steve, Two "warm" breakers next to each other can cause a trip also. Even in my stick house I move low use breakers between high draw breakers to keep them cooler. This may not be the problem but it can't hurt.
Another thing .... If you are running your fan on low in certain conditions the A/C unit can ice up and cause an increase in amp draw. JM2¢, Hank

Steve S · 07-02-2014, 11:22 AM

That makes sense hankpage, I'm starting to think that the breaker got pretty hot as it's right beside the main breaker and it was stinking hot in here yesterday when I got home.
I took the cover off the ac few mins ago and there was just the typical icing coming off the compressor tube and that was about it.
It's 80 in the shade now so I'm just going to leave it running all day and see what happens.

Steve S · 07-02-2014, 01:43 PM

K first off is there two fans in the ac? Like there's one up top but is there one in the box?
I just turned the temp down, it shut off, was sitting here and it fired up, I heard an inside fan blowing bit the one up top seemed to be just dragging to get going and poof the breaker tripped!
I flicked the breaker a few times and it did the same thing!
Does this sound like the motor up top?
Going out for a bit and I'll see what happens when I get home.

**JRTJH** · 07-02-2014, 01:59 PM

No there is only one fan in the entire package. It is a 1/2HP motor with a double shaft, the "back end" runs the fan on the evaporator and the "front end" runs the fan on the air supply ducting.

When you turn your fan adjustment (on the thermostat) from HI to LO, the fan will stop turning momentarily and then will resume in the new setting. In AUTO, if your sensed temperature is greater than 5F from the setting, the fan will operate in HI. Once the sensed temperature drops to within 4F of the setting, the fan will automatically shut down, switch to LO and resume.

The "whirring" you hear when the fan is not running is the compressor. It will not shut down during fan speed changes because it would build too much "head pressure" and not resume without increased amperage to start...

Remember (or think of) the delay that is built into every appliance with a compressor. If you turn it off, it won't turn back on until approximately a 2 minute delay to 'normalize pressure" on both sides of the compressor to prevent "hard starts".

Steve S · 07-02-2014, 02:52 PM

K that makes sense, I'm just wondering if the thermostat could be the out of whack as the breaker is only tripping when I adjust it. The ac sounds like it wants to go, then changes it's mind then it wants to go again. This only happens when it's running and I need to leave for a bit.
I just got home, flipped the breaker and everything is working fine. It's going from high to lo, shutting down and firing up again.
Should I be ruling out the breaker at this point as it seems to be doing it's job.

**JRTJH** · 07-02-2014, 04:11 PM

Do you have an accurate "metered" voltage reading of what the actual voltage is INSIDE the RV when the Air Conditioner is operating?

You may have an issue with voltage drop causing the amperage in the compressor to rise, making the circuit breaker trip when it comes back on after being off a short time.

If you've got a multimeter, test the voltage in a wall plug inside the RV while the A/C is running (and be sure to recheck it when the A/C sounds like it's loading up just before the circuit breaker trips)....

It really sounds more like a low voltage condition than a circuit breaker or A/C issue.

Steve S · 07-02-2014, 07:33 PM

I have a few good multimeters but the guys have them on a site in Van so I'll pick up a cheap one in the morn and test things out and let you know.

bsmith0404 · 07-03-2014, 02:40 AM

This hasn't been asked/mentioned yet so I'll throw it out there. Most house breakers are 10 or 20 Amp, is the circuit you are plugged into a true 30 Amp? You can't get 30 amps from a 20 amp breaker. Also is the RV the only thing plugged into it or is there additional draw? As mentioned previously, this sounds like an under-amperage issue. How many other things do you have drawing electricity in the RV when it trips? Have you noticed that it only trips when you have other items running? What is your refrigerator running on, electric or propane? I would isolate it by shutting all other power draining items off and see if it still happens.

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