My Fragmatics vacuum keeps tripping it's 30A fuse.

[Car_Wash_Guy]

Was operating normally and one day I noticed that one of its two motors was pulling much less. Was running perfectly on one Domel 492.4 and one Ametec ( Original from 2008!!).

Switch the week pulling Ametec to another Domel and noticed it starting to trip the fuse immediately. Redid the wiring nuts to connect the motors and moved some wiring around and and it started running normally. Ran continuously for a few minutes and I thought it was good until it started do the same.

Where shoudl I begin troubleshooting?

 

[MEP001]

Check or change the older motor's brushes or replace the motor.

Try MDL 10 fuses instead of fast-blow 30 amp.

 

[OurTown]

Are you checking amperage draw for each motor with a clamp on meter?

 

[Car_Wash_Guy]

Went out and bought an amp meter since I need one anyway. Tested both motors and at start up they’re drawing 25A and while running roughly 12.2 - 12.7.

The strange thing is I’ve had the vacuum off for about two days since I haven’t gotten around to testing it and it ran through a full 4 minutes cycle without a problem.

 

[OurTown]

Are you saying that you tested each individual motor or both together? If together then the amp draw seems low but if individually then your numbers seem high.

 

[Car_Wash_Guy]

I tested with an amp meter and found the older motor drawing too much. Went ahead and replaced it. Back in business.

Thanks guys

 

[Car_Wash_Guy]

Still doing it. Will run for a day, maybe day and a half and then will trip again. Could it be the relay?

 

[Earl Weiss]

Sticking relay could do that.

 

[mgmtoo]

How clean are the bags?

 

[MEP001]

How clean are the bags?

Dirty bags will reduce the amperage draw.

 

[MEP001]

Still doing it. Will run for a day, maybe day and a half and then will trip again. Could it be the relay?

Is it blowing the main 30A relay?

 

[Car_Wash_Guy]

Is it blowing the main 30A relay?

Yes

I took a shot and changed the relay out.

 

[Randy]

What size wire are you feeding the vacuum with and how far is the run from the breaker panel to the vacuum? Have you checked the connections on the commons? What is your total amp draw on start up with both motors running?

 

[mgmtoo]

Mep001 are you sure about that? Some how the motors are drawing too much amperes.

 

[MEP001]

Mep001 are you sure about that? Some how the motors are drawing too much amperes.

Am I sure about what? The dirty bags reducing the amperage draw? Absolutely. And the fuse blowing doesn't always mean the motors are drawing too many amps. Heat blows a fuse. A weak spot in the wiring will generate heat.

 

[OurTown]

Although it does not seem to make sense a motor with a fan blade will draw more amps without restrictions than if it has the flow restricted.

 

[Car_Wash_Guy]

What size wire are you feeding the vacuum with and how far is the run from the breaker panel to the vacuum? Have you checked the connections on the commons? What is your total amp draw on start up with both motors running?

Not sure. All I can say is that it's as built in 2008. Never caused a problem until I changed out the second Ametek with a Domel.

24A on start up for both. 12A +/- individually.

 

[Car_Wash_Guy]

Sticking relay could do that.

Wasn't the relay

 

[pcb]

I'm sure you've checked it, but could you have possibly gotten a motor with the wrong voltage? You could possibly block the hole for a motor and let it run on one at a time to see if it's the motor causing it. Not ideal but sounds like you've tried most everything else.