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Running 120V Motor with 240V?

M

Mio

Jan 1, 1970
0
Hi,

I've got a blower with a motor rated for 120V, and I was wondering if
it was possible to run it with 240V somehow.

I was thinking maybe phase control or something, but to be honest, I'm
not really as familiar with power electronics as I'd like.

Thoughts?

Thanks
 

neon

Oct 21, 2006
1,325
Joined
Oct 21, 2006
Messages
1,325
stick a transformer 240:120 ratio or a phase regularor or a wasting power resistor or buy the right fan
 
S

Spehro Pefhany

Jan 1, 1970
0
Hi,

I've got a blower with a motor rated for 120V, and I was wondering if
it was possible to run it with 240V somehow.

I was thinking maybe phase control or something, but to be honest, I'm
not really as familiar with power electronics as I'd like.

Thoughts?

Thanks

How big is it? Split phase? Offshore-made autotransformers are
reasonably priced up to 500W or more (>1/2 HP), but they're heavy.
Best regards,
Spehro Pefhany
 
Hi,

I've got a blower with a motor rated for 120V, and I was wondering if
it was possible to run it with 240V somehow.

Check the manufacturer's specs. Some motors have provisions for
connection as either 120V or 240V. Sometimes you will see a wiring
diagram on the inside of the motor junction box cover plate. You
might get lucky!
Jon
 
M

Mio

Jan 1, 1970
0
Thanks for the suggestions.

I'd rather not use a step-down transformer if I could avoid it
(They're a little big, and I'm not sure I have the room).

It's a PSC motor.

Thanks
 
M

Mio

Jan 1, 1970
0
Check the manufacturer's specs.  Some motors have provisions for
connection as either 120V or 240V.  Sometimes you will see a wiring
diagram on the inside of the motor junction box cover plate.  You
might get lucky!
Jon

It does not support rewiring as 240.

Do I have any options other than a transformer?

Thanks
 
P

Paul E. Schoen

Jan 1, 1970
0
Check the manufacturer's specs. Some motors have provisions for
connection as either 120V or 240V. Sometimes you will see a wiring
diagram on the inside of the motor junction box cover plate. You
might get lucky!
Jon

It does not support rewiring as 240.

Do I have any options other than a transformer?

Thanks

============================================================================

If you want to be creative, you could make a PWM motor controller, but
instead of rectifying the mains voltage and recreating a sine wave, you can
drive the bridge with the sine wave input and use diodes to steer the
voltage appropriately. Then you can use a simple 50% PWM to get 120 VAC
from 240 VAC.

I did something like this with LTspice. The ASCII file shows generic
switches that need to be replaced with a bidirectional switches, which
could
be two MOSFETs or IGBTs in series. The same effect can be done in a bridge
circuit. If the load is inductive, as a motor, it is necessary to provide a
conduction path during the OFF times, and the snubber reduces inductive
voltage spikes during transition. The RC network across the load shows the
average waveform that effectively would be seen by the motor.

Paul

============================================================================

Version 4
SHEET 1 880 680
WIRE 64 -32 -320 -32
WIRE 16 0 -256 0
WIRE 64 0 64 -32
WIRE -16 48 -48 48
WIRE 0 48 -16 48
WIRE 224 48 80 48
WIRE 304 48 224 48
WIRE 400 48 304 48
WIRE 448 48 400 48
WIRE 560 48 528 48
WIRE 592 48 560 48
WIRE 96 96 -176 96
WIRE 400 96 400 48
WIRE 464 96 400 96
WIRE 224 112 224 48
WIRE 400 112 400 96
WIRE 464 112 464 96
WIRE 176 128 -128 128
WIRE 592 128 592 48
WIRE -256 160 -256 0
WIRE -176 160 -176 96
WIRE -48 160 -48 48
WIRE 48 160 -48 160
WIRE 304 160 304 112
WIRE -48 176 -48 160
WIRE 48 176 48 160
WIRE 96 176 96 96
WIRE 176 176 96 176
WIRE 400 208 400 192
WIRE 464 208 464 192
WIRE 464 208 400 208
WIRE -320 272 -320 -32
WIRE -256 272 -256 240
WIRE -256 272 -320 272
WIRE -176 272 -176 240
WIRE -128 272 -128 128
WIRE -128 272 -176 272
WIRE -48 272 -48 256
WIRE 48 272 48 240
WIRE 48 272 -48 272
WIRE 224 272 224 192
WIRE 224 272 48 272
WIRE 304 272 304 240
WIRE 304 272 224 272
WIRE 400 272 400 208
WIRE 400 272 304 272
WIRE 592 272 592 192
WIRE 592 272 400 272
WIRE -256 304 -256 272
WIRE -128 304 -128 272
WIRE -48 304 -48 272
FLAG -48 304 0
FLAG -16 48 Vin
FLAG -256 304 0
FLAG -128 304 0
FLAG 560 48 Vout
SYMBOL res 288 144 R0
SYMATTR InstName R1
SYMATTR Value 20
SYMBOL cap 288 48 R0
SYMATTR InstName C1
SYMATTR Value 0.47µ
SYMBOL voltage -48 160 R0
WINDOW 3 23 136 Left 0
WINDOW 123 0 0 Left 0
WINDOW 39 16 99 Left 0
WINDOW 0 30 28 Left 0
SYMATTR Value SINE(0 360 60 0 0 0 150)
SYMATTR SpiceLine Rser=1
SYMATTR InstName V1
SYMBOL sw 96 48 R90
WINDOW 3 -36 -113 VRight 0
WINDOW 0 24 92 VRight 0
SYMATTR Value MySwitch
SYMATTR InstName S1
SYMBOL voltage -256 144 R0
WINDOW 3 -91 241 Left 0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
WINDOW 0 9 7 Left 0
SYMATTR Value PULSE(0 10 50u .1u .1u 49.8u 100u 3000)
SYMATTR InstName V2
SYMBOL sw 224 96 R0
WINDOW 3 -12 117 Right 0
WINDOW 0 24 92 VRight 0
SYMATTR Value MySwitch
SYMATTR InstName S2
SYMBOL voltage -176 144 R0
WINDOW 3 -171 205 Left 0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
WINDOW 0 7 7 Left 0
SYMATTR Value PULSE(0 10 0 .1u .1u 49.8u 100u 3000)
SYMATTR InstName V3
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SYMATTR InstName R2
SYMATTR Value 100
SYMBOL res 544 32 R90
WINDOW 0 0 56 VBottom 0
WINDOW 3 32 56 VTop 0
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SYMATTR Value 10k
SYMBOL cap 576 128 R0
SYMATTR InstName C2
SYMATTR Value 100n
SYMBOL ind 448 96 R0
SYMATTR InstName L1
SYMATTR Value 100m
SYMATTR SpiceLine Rser=10
SYMBOL cap 32 176 R0
SYMATTR InstName C3
SYMATTR Value 10µ
TEXT -88 496 Left 0 !.tran 100m startup
TEXT -416 464 Left 0 !.model MySwitch SW(Ron=.1 Roff=100Meg Vt=2 Vh=-.5
Lser=10n Vser=0)
 
J

Jamie

Jan 1, 1970
0
Mio said:
Hi,

I've got a blower with a motor rated for 120V, and I was wondering if
it was possible to run it with 240V somehow.

I was thinking maybe phase control or something, but to be honest, I'm
not really as familiar with power electronics as I'd like.

Thoughts?

Thanks
A simple phase control that employs a triac will work just fine.


http://webpages.charter.net/jamie_5"
 
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