The Tank › Tripping breaker
- January 17, 2011 at 11:49 pm #14979
My water has been running fine for years and now the breaker is tripping. I reset the breaker and the w/h will run for 15-20 minutes and then it trips again. I replaced the breaker (20amp single pole). With the new breaker, it’s doing the same thing. It has 2 – 4500w elements (4500w total). The old breaker didn’t have any arking marks and the wire is screwed in tight so this tells me the connection was good. What would cause the breaker to start tripping now after years of use?
ThanksJanuary 18, 2011 at 12:16 am #14981Randy SchuylerKeymaster
Think about elements and thermostats and troubleshooting. If you know how to use a voltmeter, there is a full walk-through for electric water heaters in Tanklets, for which there is a link at the top of the topic index, under Electric Water Heater Issues.
If you’ve never used a voltmeter, get a plumber to test for you, as you can be killed remarkably quickly by an electric water heater!
Randy SchuylerJanuary 18, 2011 at 3:07 am #14984
I used and have several volt/ohm meters. I’ll give that a try and report back.
ThanksJanuary 19, 2011 at 5:10 pm #14997energyexpertParticipant
4500 watts on 120 volts would be 37.5 amps. Is this 4500 watts at 240 volts and a double pole breaker? 4500 watts at 240 volts draws 18.75 amps. Circuit should be #10 AWG and a 25 or 30 amp double pole breaker. If voltage is a little high, power and current go up. If actual voltage is 250 then current goes to 19.53 amps. At this level a 20 amp breaker will get warm. If adjacent breakers are warm and/or the room is warm, the breaker can easily trip even just below the “real setpoint”. Breakers function on inverse/time and a warm breaker trips sooner than a cold one.
DavidJanuary 20, 2011 at 7:47 pm #15025
It’s on 2 separate 20 amp breakers. The breaker that continues to trip I assume is for the top element. once the breaker is reset you can tell the element is on. I’ve checked voltage and it’s 240 at the top element. I haven’t had or taken the time to investigate further…hopefully this weekend.January 23, 2011 at 10:55 am #15050EjParticipant
Jdunn on a safety note, all 220 circuits connect to the breaker panel through a double pole breaker (or equivalent fuse). Double pole breakers often look like a pair of single pole breakers that are stuck together. 220 equipment will actually function if it is connected by way of two single pole breakers like yours, but it wouldn’t be safe or up to code, because in the event of a fault one breaker might trip causing the heater to stop working, but it would still be energized by the other breaker. So double pole breakers are designed to trip both sides simultaneously.
- You must be logged in to reply to this topic.