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I have a General Electric motor starting switch (CR1061-DOA). It is connected to a 3/4 hp electric motor that powers a table saw (pictures and specs of motor here - https://woodworking.stackexchange.com/questions/13838/old-table-saw-stalls-under-load-toro).

The starter switch is currently behaving as follows:

  1. When I start the table saw without load, the saw runs for quite some time without issues. The max I've left it on without load is 15 mins.
  2. After I rip the first plank or two, the starter will trip mostly during ripping. I have to wait 2-3 mins to be able to use the saw again.
  3. Each time the starter trips, I've touched the motor surface and its mildly warm. I've never had a time where the motor surface was hot to touch.
  4. Once the starter starts tripping, even when I run it under no load, it'll trip in a few minutes.
  5. Folks at sister site woodworking tell me I should be able to rip without issues with the load I'm putting (2 inch think wood planks)

Other details: The electric motor is on 110V. Its a dual voltage motor, I switched it from 220V to 110V recently when I installed it.

What have I done:

  1. Opened the switch assembly, checked the heater, ensured no screws were loose or if there was any signs of carbon or damage.

  2. Tightened all connections to the switch

  3. Motor runs free and smooth (removed the v-belt and checked)

  4. Opened the capacitor housing, cleaned, checked connections are clean.

I'd like to basically replace the starter switch but this being a very old switch, its not easy to find and replace. Could I get the inside black switch instead? I'd like to replace the heater and the connector inside the box. Or can I replace it with something else.

I'm assuming here that the motor is good. And that the capacitor isn't the culprit.

inside of motor starter switch

motor starter switch

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    A) that looks like it's switching the neutral wire, not the hot wire. That makes for a dangerous situation as the motor is always energized. B) It's time to replace that relic with a modern safety switch with a recessed "ON" button and a very large, easy to press "OFF" paddle.
    – FreeMan
    Commented Aug 30, 2022 at 17:19
  • That is not a switch. It is a 6 Amp circuit breaker
    – DIY75
    Commented Aug 30, 2022 at 17:36
  • Motor amp is 10.8. But the 'switch' is rated 6A!
    – Regmi
    Commented Aug 30, 2022 at 17:45
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    Are you aware it will draw twice the current at 120V?
    – user28910
    Commented Aug 30, 2022 at 17:49
  • No, didn't know it's drawing twice the current. So then the core issue is that the switch is not sized properly, for use with 110V? (The previous owner had a 220V connection)
    – Regmi
    Commented Aug 30, 2022 at 17:53

1 Answer 1

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Motor power is proportional to its supply voltage times current. When you rewired the motor, you halved the voltage, so its current draw doubled. That is why the nameplate lists the current as 10.8/5.4 A. (Note that this current is at rated load, 3/4 HP in this case)

These motor starting switches (aka Manual Starters) normally have a replaceable heater element that is sized for the full-load current of the motor. The purpose of the heater is overload protection of the motor. The heater for this switch is apparently sized for 5.4 full load amps at 230V supply; you need to find one that is sized for 10.8 Amps. If you can't find a 10.8 A heater for this old switch, you should replace the switch. If you do replace the switch, make sure to get a correct sized heater; they are sold separately.

I wouldn't recommend using just a regular switch without overload protection, because you might find yourself looking for a new motor in the future.

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  • I could only find a 12.5A heater element instead of 10.8A. How much of an issue is this? (Heater Elements are hard to find it seems.)
    – Regmi
    Commented Aug 30, 2022 at 19:39
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    @Regmi - You probably won't find one for exactly 10.8A. 12.5 is 16% higher than rated, so maybe 40% more copper losses, comparable increase in temperature rise, maybe another 25 degrees if you're operating overloaded for long stretches. But you aren't (unless you're doing some serious ripping) , so it should be able to tolerate an occasional shorter-term overload. I think I'd be okay with it.
    – user28910
    Commented Aug 30, 2022 at 20:34
  • thank you for the detailed analysis. I'm a hobbyist so when I need to, I only use the table saw for 20 mins max. Generally, it'll be for short bursts a few mins each.
    – Regmi
    Commented Aug 30, 2022 at 20:42
  • It turned out the heater element for 12A is different than the one I have. But luckily they had the entire switch as well. So I bought them both. After I figured the wiring and connected it, it was a new machine! I ripped a lot of wood today. Can't thank you enough!
    – Regmi
    Commented Aug 31, 2022 at 5:04

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