How many amps for a 2 motor vac

[slash007]

Does anyone know how many amps a typical 2 motor vac draws at start up and while running? Thanks.

 

[I.B. Washincars]

I think it's about 7 amps per motor. I'm not sure if it's more at start-up.

 

[MEP001]

It's a lot more at start-up, between 60 and 65 amps total. Standard 20-amp breakers should handle the high start load even though some manufacturers like Fragramatics call for 30-amp service.

Running load varies a little between brands of motors, but they're usually around 13 amps with the top door of the vac open.

 

[Greg Pack]

I don't know what the inrush is, but I've never had trouble running a 2 motor vac off a 20 amp circuit.

 

[slash007]

I haven't had any issues running my vacs on 20 amp breakers and 10 gauge wire, but I had one vac that seems to have the hot wire burned up under ground and was considering tying it into the nearby vac and running them off of a 30 amp breaker until I can get the wires replaced. I did run 2 Adams vacs that way for a couple of years in the past and never had any issues, but was worried about running these 2 JC combo vacs together. They are 2 of my least used vacs and my theory is that it would be very rare for both to be running at the same exact time as other vacs usually get used first and then people just park in front of them and dry for a while. I am just worried of the wire overheating then having more issues.

 

[MEP001]

Odds are the wire underground got wet and corroded through. In my experience, wires don't burn up underground, they burn up at the ends where the connections are weakest.

You're safe running two vacs on a 30-amp breaker especially with 10 gauge wire.

 

[slash007]

I'm sure it got wet, that's what happened a few years ago when I changed out all the lines. I was able to pull through the same conduit, I'm sure there is a break somewhere letting water in. I knew 10 gauge would be ok, unfortunately I meant to say it's 12 gauge wire running to the vacs. Think it would still be ok to run 2 vacs on that same wire?

 

[mjwalsh]

I'm sure it got wet, that's what happened a few years ago when I changed out all the lines. I was able to pull through the same conduit, I'm sure there is a break somewhere letting water in. I knew 10 gauge would be ok, unfortunately I meant to say it's 12 gauge wire running to the vacs. Think it would still be ok to run 2 vacs on that same wire?

Even though wire to Vacs can be rated for direct burial ... I think using non corroding conduit is always a better long term choice.

Usually 15 amp breaker for 14 ga. 20 amp for 12 ga. 30 amp for 10 gauge. There are other technicalities & exceptions such as too crowded boxes, lower quality wire & insulation of specific same gauge wire etc.

It was a real shocking visual for me to see on a mission trip back in 1998 to the mountains of Guatemala ... scrap wire of who knows what mixed gauge & quality etc strung overhead in haphazard ways.

 

[Greg Pack]

The breaker will protect the hot but not the neutral.

 

[Car_Wash_Guy]

For a 3 motor vac what would you guys suggest? 30A with 10 ga?

 

[I.B. Washincars]

For a 3 motor vac what would you guys suggest? 30A with 10 ga?

That's what I have and have always been told.

 

[tdlconceptsllc]

For a 3 motor vac what would you guys suggest? 30A with 10 ga?

Yes that's the requirement I have 3 motor vacs & that's what fragramatic requires.

 

[Greg Pack]

For a 3 motor vac what would you guys suggest? 30A with 10 ga?

Yes, IIRC you are not supposed to run a circuit over 80% of rated capacity, so you're supposed to limit a 20 amp circuit to 16 amp load, etc. So your next logical step up from a 20 amp with 12 gauge wire is a 30 amp with 10 gauge wire.

Having said that, I wouldn't bother rewiring a 20 amp circuit to accept a three motor vac. If the bags are clean and gaskets and motors are good a two motor vac works well, at least at my elevation. I have heard higher elevation sites might need three motors, but I don't know that for sure.

 

[MEP001]

I'm sure it got wet, that's what happened a few years ago when I changed out all the lines. I was able to pull through the same conduit, I'm sure there is a break somewhere letting water in. I knew 10 gauge would be ok, unfortunately I meant to say it's 12 gauge wire running to the vacs. Think it would still be ok to run 2 vacs on that same wire?

The wire probably got nicked while being pulled, otherwise it should survive fine in water. Worst case scenario, something shifted and broke the conduit and severed the wire, in which case you won't get new ones pulled through.

I have seen (many times) two vacs running on 12 gauge wire on a 20 amp breaker without a problem.

 

[MEP001]

Even though wire to Vacs can be rated for direct burial ... I think using non corroding conduit is always a better long term choice.

Except that most areas of the US don't allow wires to be "direct buried" in a commercial environment.

Usually 15 amp breaker for 14 ga. 20 amp for 12 ga. 30 amp for 10 gauge.

The length of the wire run from the breaker also takes part in determining the wire gauge.

There are other technicalities & exceptions such as too crowded boxes, lower quality wire & insulation of specific same gauge wire etc.

That's what local code is for.

 

[slash007]

The wire probably got nicked while being pulled, otherwise it should survive fine in water. Worst case scenario, something shifted and broke the conduit and severed the wire, in which case you won't get new ones pulled through.

I have seen (many times) two vacs running on 12 gauge wire on a 20 amp breaker without a problem.

I'll probably just tie the 2 vacs together for now as I try to troubleshoot. Stupid junction boxes on the way to this vac are under other vacs and I can't get the bolts loose to lift those vacs and access the junction box. I didn't have issues pulling wire in the past and there were broken wires underground, so getting nicked is probably what happened.

 

[MEP001]

Try some CRC "Knock'er Loose" on the bolts. I picked some up the other day, and it works better than anything I've ever used before, including PB Blaster. Everything I've used it on came loose easily and immediately.

 

[slash007]

Try some CRC "Knock'er Loose" on the bolts. I picked some up the other day, and it works better than anything I've ever used before, including PB Blaster. Everything I've used it on came loose easily and immediately.

Just ordered a can from Amazon. Will give her a shot! Would be awesome if it works. Thanks.

 

[Jeff_L]

I am not an electrician, but in my opinion, if there is room, run the 10ga wire out to the vac. That way if you ever replace it with something that requires more draw, then you will already be ready to go.

 

[slash007]

I do plan on upgrading the wire once I figure out how to remove the vacs covering 2 of the junction boxes. Thanks.