On Mar 29, 9:36 am, boden wrote:
I have a Nutone central vacuum on a dedicated 20 amp, 120v circuit. The
vacuum is spec'd to draw 12.6 amps (I measure it at closer to 13.5 amps)
but the starting current is close to twice that. Consequently the
breaker opens at least half the time at start-up.

Does Square D make a QO 20 amp breaker with a delay characteristic?
Perhaps a thermal breaker?

Although the circuit is dedicated, running 10AWG in order to put in a 30
amp breaker will not be fun.

Thanks,
Boden
Yes, I think they do, just for that reason.

I have a Nutone central vacuum on a dedicated 20 amp, 120v circuit. The
vacuum is spec'd to draw 12.6 amps (I measure it at closer to 13.5 amps)
but the starting current is close to twice that. Consequently the
breaker opens at least half the time at start-up.

Does Square D make a QO 20 amp breaker with a delay characteristic?
Perhaps a thermal breaker?

Although the circuit is dedicated, running 10AWG in order to put in a 30
amp breaker will not be fun.

Thanks,
Boden

"boden" wrote in message
...
I have a Nutone central vacuum on a dedicated 20 amp, 120v circuit. The
vacuum is spec'd to draw 12.6 amps (I measure it at closer to 13.5 amps)
but the starting current is close to twice that. Consequently the
breaker opens at least half the time at start-up.

Does Square D make a QO 20 amp breaker with a delay characteristic?
Perhaps a thermal breaker?

Although the circuit is dedicated, running 10AWG in order to put in a 30
amp breaker will not be fun.

Thanks,
Boden


A standard QO circuit breaker is rated for that initial motor surge. The
easiest thing to do is replace the circuit breaker, however the fact that
your motor is drawing more than its nameplate rating is a concern. It's
possible that your motor is on its way out or something is causing it to
work harder then it should. Did you check the voltage under load?

Meter reading will varty depending on the type meter you have.

True rms?



On Thu, 29 Mar 2007 10:36:48 -0500, boden wrote:

I have a Nutone central vacuum on a dedicated 20 amp, 120v circuit. The
vacuum is spec'd to draw 12.6 amps (I measure it at closer to 13.5 amps)
but the starting current is close to twice that. Consequently the
breaker opens at least half the time at start-up.

Does Square D make a QO 20 amp breaker with a delay characteristic?
Perhaps a thermal breaker?

Although the circuit is dedicated, running 10AWG in order to put in a 30
amp breaker will not be fun.

Thanks,
Boden

"boden" wrote in message
...
I have a Nutone central vacuum on a dedicated 20 amp, 120v circuit. The
vacuum is spec'd to draw 12.6 amps (I measure it at closer to 13.5 amps)
but the starting current is close to twice that. Consequently the breaker
opens at least half the time at start-up.

How long has this been occurring? Perhaps something has changed? The three
easiest solutions a

1/ Tighten all the screws. The wires going to breakers in the panel often
get a little loose over time. Turn off the main power first!
2/ Does the Nutone have a capacitor type motor? It might be defective (the
capacitor).
3/ Try a new breaker.

boden writes:
I have a Nutone central vacuum on a dedicated 20 amp, 120v circuit. The
vacuum is spec'd to draw 12.6 amps (I measure it at closer to 13.5 amps)
but the starting current is close to twice that. Consequently the
breaker opens at least half the time at start-up.

Sounds like you have a weak breaker. A 20 amp breaker should take at
least 20 seconds or so to trip when the load is 40 amps. Your load is
apparently around 25 amps, and at that current it should take many
minutes to trip. Meanwhile, the central vac should be up to speed, and
the current down at 13.5 A, in less than 20 seconds.

Here's an example trip curve for one model of QO breaker. The same site
has many others if you know exactly which model of breaker you have.

http://ecatalog.squared.com/pubs/Cir.../QO/730-11.pdf

Dave

(Dave Martindale) writes:
boden writes:
I have a Nutone central vacuum on a dedicated 20 amp, 120v circuit. The
vacuum is spec'd to draw 12.6 amps (I measure it at closer to 13.5 amps)
but the starting current is close to twice that. Consequently the
breaker opens at least half the time at start-up.

Another example: our central vac is a two-stage (two fans in series, two
motors) rated somewhere around 13 A. It's plugged into a circuit with a
15 A breaker. It *never* trips the breaker when started.

Dave

On Thu, 29 Mar 2007 10:36:48 -0500, boden wrote:

I have a Nutone central vacuum on a dedicated 20 amp, 120v circuit. The
vacuum is spec'd to draw 12.6 amps (I measure it at closer to 13.5 amps)
but the starting current is close to twice that. Consequently the
breaker opens at least half the time at start-up.

Does Square D make a QO 20 amp breaker with a delay characteristic?
Perhaps a thermal breaker?

Although the circuit is dedicated, running 10AWG in order to put in a 30
amp breaker will not be fun.

Thanks,
Boden


Seems strang, have you tried swapping another 20a breaker in?

tom @ www.Consolidated-Loans.info