Have had the same set up for the past three years with no changes or issues.
240 v unit, 30 amp breaker. Twice in three days the heater has sparked and
tripped the breaker. Open the cover and everything is hooked up but one
connection, supply side of the thermostat, has evidence of arching. Cut the
burned wire nut off, stripped the wires and reconnected. Two days later it
happens again. Still a loose connection or other possibilities?

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On Tue, 3 Mar 2020 20:14:01 +0000, Skyhawk
m wrote:

Have had the same set up for the past three years with no changes or issues.
240 v unit, 30 amp breaker. Twice in three days the heater has sparked and
tripped the breaker. Open the cover and everything is hooked up but one
connection, supply side of the thermostat, has evidence of arching. Cut the
burned wire nut off, stripped the wires and reconnected. Two days later it
happens again. Still a loose connection or other possibilities?

I bet the bottom element is covered in sediment and burned out.
Disconnect it to verify. (both sides) Wirenut the bare wires before
you power back on.
If so, it is water heater time.,

On Tuesday, March 3, 2020 at 4:56:47 PM UTC-5, wrote:
On Tue, 3 Mar 2020 20:14:01 +0000, Skyhawk
m wrote:

Have had the same set up for the past three years with no changes or issues.
240 v unit, 30 amp breaker. Twice in three days the heater has sparked and
tripped the breaker. Open the cover and everything is hooked up but one
connection, supply side of the thermostat, has evidence of arching. Cut the
burned wire nut off, stripped the wires and reconnected. Two days later it
happens again. Still a loose connection or other possibilities?

I bet the bottom element is covered in sediment and burned out.
Disconnect it to verify. (both sides) Wirenut the bare wires before
you power back on.
If so, it is water heater time.,

He said baseboard heater, not water heater. Can't diagnose from here, but the terminal could be going bad, poor connection = heat and it burns up.

On Tue, 3 Mar 2020 16:39:01 -0800 (PST), trader_4
wrote:

On Tuesday, March 3, 2020 at 4:56:47 PM UTC-5, wrote:
On Tue, 3 Mar 2020 20:14:01 +0000, Skyhawk
m wrote:

Have had the same set up for the past three years with no changes or issues.
240 v unit, 30 amp breaker. Twice in three days the heater has sparked and
tripped the breaker. Open the cover and everything is hooked up but one
connection, supply side of the thermostat, has evidence of arching. Cut the
burned wire nut off, stripped the wires and reconnected. Two days later it
happens again. Still a loose connection or other possibilities?

I bet the bottom element is covered in sediment and burned out.
Disconnect it to verify. (both sides) Wirenut the bare wires before
you power back on.
If so, it is water heater time.,

He said baseboard heater, not water heater. Can't diagnose from here, but the terminal could be going bad, poor connection = heat and it burns up.

I guess I just have water heaters on my mind. I did 2 last week. Sorry
for the confusion
If you have a friend with a clamp on ammeter, that would be the place
to start. A loose connection will get hot but I doubt it is tripping
the breaker unless the insulation is damaged and shorting to the
frame.

On 3/3/2020 7:39 PM, trader_4 wrote:
On Tuesday, March 3, 2020 at 4:56:47 PM UTC-5, wrote:
On Tue, 3 Mar 2020 20:14:01 +0000, Skyhawk
m wrote:

Have had the same set up for the past three years with no changes or issues.
240 v unit, 30 amp breaker. Twice in three days the heater has sparked and
tripped the breaker. Open the cover and everything is hooked up but one
connection, supply side of the thermostat, has evidence of arching. Cut the
burned wire nut off, stripped the wires and reconnected. Two days later it
happens again. Still a loose connection or other possibilities?

I bet the bottom element is covered in sediment and burned out.
Disconnect it to verify. (both sides) Wirenut the bare wires before
you power back on.
If so, it is water heater time.,

He said baseboard heater, not water heater. Can't diagnose from here, but the terminal could be going bad, poor connection = heat and it burns up.


Probably time to trash it if not sure of the problem. Cost $30 or so
not to burn the house down.

On Tue, 3 Mar 2020 20:14:01 +0000, Skyhawk
m wrote:

Have had the same set up for the past three years with no changes or issues.
240 v unit, 30 amp breaker. Twice in three days the heater has sparked and
tripped the breaker. Open the cover and everything is hooked up but one
connection, supply side of the thermostat, has evidence of arching. Cut the
burned wire nut off, stripped the wires and reconnected. Two days later it
happens again. Still a loose connection or other possibilities?
Still arcing? or just tripping the breaker? I'd change the breaker
if you do not have evidence or arcing and replace the heater (or the
thermostat) if there is.

On Tue, 03 Mar 2020 16:55:58 -0500, wrote:

On Tue, 3 Mar 2020 20:14:01 +0000, Skyhawk
om wrote:

Have had the same set up for the past three years with no changes or issues.
240 v unit, 30 amp breaker. Twice in three days the heater has sparked and
tripped the breaker. Open the cover and everything is hooked up but one
connection, supply side of the thermostat, has evidence of arching. Cut the
burned wire nut off, stripped the wires and reconnected. Two days later it
happens again. Still a loose connection or other possibilities?

I bet the bottom element is covered in sediment and burned out.
Disconnect it to verify. (both sides) Wirenut the bare wires before
you power back on.
If so, it is water heater time.,
I thought he said "baseboard heater" - didn't he???

On Tue, 03 Mar 2020 20:10:14 -0500, wrote:

On Tue, 3 Mar 2020 16:39:01 -0800 (PST), trader_4
wrote:

On Tuesday, March 3, 2020 at 4:56:47 PM UTC-5, wrote:
On Tue, 3 Mar 2020 20:14:01 +0000, Skyhawk
m wrote:

Have had the same set up for the past three years with no changes or issues.
240 v unit, 30 amp breaker. Twice in three days the heater has sparked and
tripped the breaker. Open the cover and everything is hooked up but one
connection, supply side of the thermostat, has evidence of arching. Cut the
burned wire nut off, stripped the wires and reconnected. Two days later it
happens again. Still a loose connection or other possibilities?

I bet the bottom element is covered in sediment and burned out.
Disconnect it to verify. (both sides) Wirenut the bare wires before
you power back on.
If so, it is water heater time.,

He said baseboard heater, not water heater. Can't diagnose from here, but the terminal could be going bad, poor connection = heat and it burns up.

I guess I just have water heaters on my mind. I did 2 last week. Sorry
for the confusion
If you have a friend with a clamp on ammeter, that would be the place
to start. A loose connection will get hot but I doubt it is tripping
the breaker unless the insulation is damaged and shorting to the
frame.
I've seen breakers tripped by arcing - and NOT arc-fault breakers
either - if they are close to the load limit.

On Tuesday, March 3, 2020 at 10:12:50 PM UTC-5, Clare Snyder wrote:
On Tue, 3 Mar 2020 20:14:01 +0000, Skyhawk
m wrote:

Have had the same set up for the past three years with no changes or issues.
240 v unit, 30 amp breaker. Twice in three days the heater has sparked and
tripped the breaker. Open the cover and everything is hooked up but one
connection, supply side of the thermostat, has evidence of arching. Cut the
burned wire nut off, stripped the wires and reconnected. Two days later it
happens again. Still a loose connection or other possibilities?
Still arcing? or just tripping the breaker? I'd change the breaker
if you do not have evidence or arcing and replace the heater (or the
thermostat) if there is.

He posted:


" Twice in three days the heater has sparked and
tripped the breaker. Open the cover and everything is hooked up but one
connection, supply side of the thermostat, has evidence of arching. Cut the
burned wire nut off, stripped the wires and reconnected. Two days later it
happens again."


A bad breaker doesn't produce arcing in connections. I missed the wire
nut part, I thought he was talking about a screw terminal. If they get
loose, overheat, they burn and even if you reconnect, it may have
enough resistance that it happens again, ie the terminal is shot.
But since he says wire nut, the next question is, did he use a new wire
nut or reuse the old one. Same issue there, if it's been arcing, gets
toasted it could have resistance, but seems less likely, because the
wires should really be twisted together and have enough contact so
just the mechanical action of the wire nut is enough. And next
question is if he's correctly applying the wire nut. With a new wire
nut, wire stripped and it looks clean not burned, with the nut
correctly applied, there can't be arcing, heating, etc.