Hi All,

I need some help. I need to find away to power a British 240V 3600W vacuum from a USA generator that has a NEMA plug socket.

The NEMA plug has 2 x 120V lives and a Neutral and Earth

I have spoken with the factory that produces the vacuums, but they don't know how to setup the vacuum to accept both 120V Lives to create 240V. Bit odd, but I need tp provide some help on this.

Anybody have any experience with this?

Regards

 

So do you measure 240V across the two lives?
If so then just connect the vacuum 240V wires to those two lives.

 

Hi, I did wonder that, but I have been advised by many people that link the two lives together (by loop wire or twisting together) would cause an issue. What do you think about this? Electricians say no, but i'm not sure about generator lives?

 

noooo.... do not do THAT....
measure voltage across two live wires... if the measurement is 240V, connect your load to those wires (treat one of the 120V phase as "UK_neutral" and another 120V phase as "UK_hot"))

 

but I have been advised by many people that link the two lives together (by loop wire or twisting together) would cause an issue.

Yes it most certainly would cause an issue. That would likely short the generator output.

I meant you measure the voltage between the two generator "lives" and, if its 240V, then you connect one "live" to one of the vacuum 240V wires and the other "live" to the other vacuum 240V wire.

 

We actually did this, wired one 120v live to the neutral and the other live to the live on the vacuum. It powers up, but i'm not sure about the power as it sounds like a 2000W vacuum and also sucks at the same rate as the 2000W and should be 3600W.

My question is, would this wiring cause any harm to the vacuum. I'm not sure how the internals such as capacitors etc if relevant would react to a feed coming in the wrong way when the neutral normally acts as a return.

Also, is there any way of testing if the vacuum is actually powering 240v, even though I know across both wires I get 240V. I'm not sure how the vacuum acts with this power coming in from two angles!

Thank you again.

 

why don't you post detail from generator nameplate?
how about vacuum generator nameplate?
pictures speak louder than words...

 

Also, is there any way of testing if the vacuum is actually powering 240v, even though I know across both wires I get 240V. I'm not sure how the vacuum acts with this power coming in from two angles!

The angle has nothing to do with it.
Angle only pertains if you have more than one phase, and here you only have one.

What is the generator power rating?
If the vacuum doesn't seem to be getting enough power, measure the voltage when the vacuum is running.
If it's still at least 220V then it's getting all it should need.

 

50 or 60 Hz?

 

We are trying to get it run with any make generator as long as it has a NEMA L14-30P socket and is over 5KVA as the vacuum is:

240V Single Phase
50Hz but can run on 60Hz no problem
3600W output across 3 motors (switches)

I am just getting a meter to measure the voltage and wattage draw for the machine on the configuration of one hot on uk live and one hot on uk neutral.

So now my main concern is can the vacuum operate in this way without burning out the vacuum internal components? Does a hot up the neutral affect any circuitry?

 

Are we talking about a vacuum pump motor?

 

Does a hot up the neutral affect any circuitry?

Neutral is not any different than the hot, except it should be connected to earth/chassis ground at some point on the generator end.
If the vacuum neutral connection is not connected to the vacuum chassis (and I assume it's not) then it should be no different electrically from the hot connection. You are just connecting to the two motor leads, each of which is isolated from the chassis.
But the chassis should be connected to the earth safety ground
Does the vacuum only have two connections?

 

Sorry, Vacuum Cleaner - Wet and Dry Commercial Use

 

Neutral is not any different than the hot, except it should be connected to earth/chassis ground at some point on the generator end.
If the vacuum neutral connection is not connected to the vacuum chassis (and I assume it's not) then it should be no different electrically from the hot connection. You are just connecting to the two motor leads, each of which is isolated from the chassis.
But the chassis should be connected to the earth safety ground
Does the vacuum only have two connections?

Yes the vacuum only has 2 wire, currently 1 live and 1 neutral, thanks

 

Yes the vacuum only has 2 wire, currently 1 live and 1 neutral, thanks

For safety, I would change to a three wire cable with the third connected to the vacuum machine chassis at one end and the generator safety ground connection at the other.

 

For safety, I would change to a three wire cable with the third connected to the vacuum machine chassis at one end and the generator safety ground connection at the other.

Hi, this is a class 2 item and a plastic headed unit so the factory have said it would have no need to be earthed. But this is based on the uk setup, is it the same for the USA, I would imagine so, but i'm not 100%, thanks

 

Hi, this is a class 2 item and a plastic headed unit so the factory have said it would have no need to be earthed. But this is based on the uk setup, is it the same for the USA, I would imagine so, but i'm not 100%, thanks

I believe that's considered to be a double-insulated device and, my understanding is that such devices don't need a safety ground connection in the USA.