MR Toggle

[Alwayslearningelec]

Anyone know why all motor rated toggle switches are either 2 or 3 pole but many times they are part of a single phase motor being fed from a 1P breaker? Wouldn’t you need a 1P motor rated toggle? Thanks.

 

[infinity]

If it's a small motor a simple motor rated snap switch will do for a 1 pole application.

https://rexel-cdn.com/Products/Leviton/1221-2E.pdf?i=9738F613-CF7A-4CE0-AA9D-CA676D28C17C

 

[don_resqcapt19]

The UL Guide information for Snap Switches (WJQR) says:
{quote]
AC-only general-use snap switches rated up to 277 V AC are suitable for the control of:

• Resistive loads not exceeding the marked amp and voltage rating of the switch.
• Inductive loads not exceeding the marked amp and voltage rating of the switch.
• Electric discharge lamp loads not exceeding the marked amp and voltage rating of the switch.
• Tungsten-filament lamp loads at 120 V AC up to the full current rating of the switch.
• Electronic ballast, self-ballasted lamp, compact fluorescent lamp, and LED driver lamp loads up to 20 A, but not exceeding the amp rating of the switch at its marked voltage rating.
• Motor loads up to 80% of the amp rating of the switch, but not exceeding 2 hp.[/quote]

 

[kwired]

Anyone know why all motor rated toggle switches are either 2 or 3 pole but many times they are part of a single phase motor being fed from a 1P breaker? Wouldn’t you need a 1P motor rated toggle? Thanks.

Most motors that operate at 120 volts don't exceed the rating of heavier duty general purpose toggle switches anyway.

Nothing prohibits using only one pole of a multi-pole switch if you do need the motor rated switch.

Look at the switch rating for use on 120 volts, it won't necessarily be 1/2 rating as for 240 volts in every instance.

A motor controller does not need to break all lines either, just enough lines to stop current flow, so 1 line of a single phase motor and two lines of a three phase motor. If it is also a disconnecting means it must break all ungrounded conductors though.

 

[infinity]

This is from the link in post #2. You'll see that it's rated for 1 HP @ 120 volts which is 16 amps. That also complies with the last item in Don's list.

Description
20 Amp, 120/277 Volt, Toggle Single-Pole AC Quiet Switch, Industrial Grade, Self
Grounding, Back & Side Wired, - Brown
Product Features
Grounding: Self Grounding
Amperage: 20 Amp
Voltage: 120/277 Volt
HP Rating: 1HP-120V 2HP-240V-277V
Max. Amperage: 16 Amp
Termination: Back & Side
Actuator Material: Thermoplastic
Body Material: Thermoplastic
Strap Material: Steel
Color: Brown
Standards and Certifications: UL/CSA
Warranty: 10 Year Limited