Dooger54
Well-known member
Pretty simple question-
Do I need all power off, battery and shore power, before testing continuity?
Do I need all power off, battery and shore power, before testing continuity?
Testing continuity on auto reset breaker
- Thread starter Dooger54
- Start date
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Gary RV_Wizard
Site Team
Continuity doesn't depend on external power - it measures ohms (resistance) and makes a circuit that runs through the meter. It's safest and easiest to do that with the RV power off, but it is not a requirement.
Heli_av8tor
Well-known member
Strongly Disagree. It is a requirement on many levels.
Tom
Tom
Checking continuity with power on using a volt meter. Put the volt meter on the terminals on input and output side using the scale appropriate tor the voltage. If you read the voltage being switched, the contacts are open. If you read zero or nearly zero, switch to the lowest scale on the meter. If the contacts are closed, the meter should read 0.5 volts or less.
Heli_av8tor
Well-known member
ChasA: I agree that measuring as you describe tells you more about the breakers condition. But this is outside of the way the OP phrased the question and perhaps above his comfort level.
Gary RV_Wizard
Site Team
An ohmeter forms its own circuit through the device using its own power (battery). If the external power doesn't blow out the meter, it works fine with power present. Even cheap meters handle the presence of external 12vdc or 120vac OK.
Using a voltmeter is an indirect check on continuity. If you have voltage (to ground or neutral) on both sides of the breaker, it is probably closed. I say probably because backfeed into the circuit could make that test invalid
Using a voltmeter is an indirect check on continuity. If you have voltage (to ground or neutral) on both sides of the breaker, it is probably closed. I say probably because backfeed into the circuit could make that test invalid
Dooger54
Well-known member
Just to be safe I will disconnect all power. Don?t want to risk blowing the meter. Good discussion here !
xrated
Well-known member
Step 1. Remove the incoming power lead from the breaker (not the load side lead)
Step 2. Put your ohmmeter on the ohms scale
Step 3. Place your leads on the terminals of the breaker and read the ohms that the breaker has
Step 4. Once you have a reading, then determine if you need a new breaker or the old one is still good.
The amount of ohmage through a heave set of contacts like the breaker you are testing should normally read less than one ohm. You may not be able to tell exactly, depending on the quality of your ohmmeter and and whether or not it is a digital vs. an analog meter.
Step 5. Make sure that if you are going to have to replace the breaker and wait to get a new one, tape that wire until you get the new one and replace it. If it's good, go ahead and reconnect the wire. The safest way for both you and your meter is to always remove power before testing continuity/ohms of a circuit.
Step 2. Put your ohmmeter on the ohms scale
Step 3. Place your leads on the terminals of the breaker and read the ohms that the breaker has
Step 4. Once you have a reading, then determine if you need a new breaker or the old one is still good.
The amount of ohmage through a heave set of contacts like the breaker you are testing should normally read less than one ohm. You may not be able to tell exactly, depending on the quality of your ohmmeter and and whether or not it is a digital vs. an analog meter.
Step 5. Make sure that if you are going to have to replace the breaker and wait to get a new one, tape that wire until you get the new one and replace it. If it's good, go ahead and reconnect the wire. The safest way for both you and your meter is to always remove power before testing continuity/ohms of a circuit.
John From Detroit
Well-known member
On an auto reset circuit breaker I would check with power on..
Check for 12 volts on both terminals (Well I use a test light so it's Bright LIght on both terminals) if the light is equally bright or the voltage is within a very tiny fraction of a volt the same on both sides of the breaker. Continuity confirmed.
If one side bright (Battery voltage) and the other side DARK, Continuity does not exist.
Check for 12 volts on both terminals (Well I use a test light so it's Bright LIght on both terminals) if the light is equally bright or the voltage is within a very tiny fraction of a volt the same on both sides of the breaker. Continuity confirmed.
If one side bright (Battery voltage) and the other side DARK, Continuity does not exist.
