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240v 1.5hp motor

Gutt3r03

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I have a Schneider 4048 120/240 48v Running a 1.5hp motor on 120v the contacts would chatter. Changed it to 240v and now the inverter will not run motor. Hooked motor to 240v power from my shop and it runs motor flawlessly. Please help.
 
Surge on a 1.5hp motor is likely North of 8,000W

Does the motor have an LRA rating? If so, this is likely over your inverter's surge rating.

If no LRA, does the motor have a run current rating? If so, surge is typically about 5X the run rating.
 
Surge on a 1.5hp motor is likely North of 8,000W

Does the motor have an LRA rating? If so, this is likely over your inverter's surge rating.

If no LRA, does the motor have a run current rating? If so, surge is typically about 5X the run rating.
 

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If it’s drawing 8000w and the inverter is rater at 7000w would it be anything I could do with motor (soft start or any kind) of modifications I could do to make it work ?
 
It didn't use to do this?

Voltage drop is one cause for relay chatter. Can you compare the voltage on the relay when on the inverter vs. the grid?
 
Is there any load on it when starting?

Not sure if this would help for an induction motor, but ...
What if you wire the motor for 240V, and rig a switch so it is connected to 120V from inverter. Turn on motor, then after it starts flip switch so it gets 240V from inverter.

This may not work (if it sits there humming without starting, turn off immediately before it overheats.) Induction motors need a lot of current to start, and at half voltage may not turn.

You mentioned contacts. The only contacts I'm familiar with in an induction motor are for starting windings, and they don't open until centrifugal mechanism is spinning.

Is it capacitor start? Capacitor run?
Looks like 2 capacitors:


LRA for Mtr2-1P5-1AB18 110/55 Amps, would like 13kVA for a couple seconds:


Yes, soft starts are supposed to help. The good ones are several hundred dollars.
 
It didn't use to do this?

Voltage drop is one cause for relay chatter. Can you compare the voltage on the relay when on the inverter vs. the grid?
I’m trying to get this machine setup in my trailer. Compare voltage in what way?
 
That motor is going to pull north of 35A during startup on 240V on 120V, it likely pulled 75A.
Around 8400W from an inverter.
A 300$ soft starter, or a variac might let it start slower and slowly reach full rpm without excessive amp draw.
 
Is there any load on it when starting?

Not sure if this would help for an induction motor, but ...
What if you wire the motor for 240V, and rig a switch so it is connected to 120V from inverter. Turn on motor, then after it starts flip switch so it gets 240V from inverter.

This may not work (if it sits there humming without starting, turn off immediately before it overheats.) Induction motors need a lot of current to start, and at half voltage may not turn.

You mentioned contacts. The only contacts I'm familiar with in an induction motor are for starting windings, and they don't open until centrifugal mechanism is spinning.

Is it capacitor start? Capacitor run?
Looks like 2 capacitors:


LRA for Mtr2-1P5-1AB18 110/55 Amps, would like 13kVA for a couple seconds:


Yes, soft starts are supposed to help. The good ones are several hundred dollars.
The motor is on a elbow machine for bending downspout elbows. Yes has 2 capacitors on motor.
 
That motor is going to pull north of 35A during startup on 240V on 120V, it likely pulled 75A.
Around 8400W from an inverter.
A 300$ soft starter, or a variac might let it start slower and slowly reach full rpm without excessive amp draw.
Do you recommend any certain brand of soft start?
 
I’m trying to get this machine setup in my trailer. Compare voltage in what way?
Hmnn... Do you have a part number and wiring diagram for the guttering machine? Push pedal to start?

Is your inverter "ON" or in "search" mode when you trying to use it?
 
Consider brush-type "universal motors". They will start with less current, and run at lower voltage (so start at 120V, run at 240V works well.)

I haven't found one quickly, but here is a 48VDC motor:


Here's a 1 HP 115V universal motor, but 10,000 RPM so needs speed reducer


3/4 HP 12V


1.5 HP 48V

 
Update on motor I checked the inrush today and from what I’ve been told should be around 35a but it’s 56a inrush running with a load it’s 5A and no load it’s 3a. Could the motor have an internal issue? With what the numbers are on the tag it exceeds those numbers.
 
Update on motor I checked the inrush today and from what I’ve been told should be around 35a but it’s 56a inrush running with a load it’s 5A and no load it’s 3a. Could the motor have an internal issue? With what the numbers are on the tag it exceeds those numbers.
Spot inrush can easily exceed 10x running amps under load…
 
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