Amperage question

[Hot shot]

How many amps does a 230 volt 1/2hp well pump draw
The tag on the pressure tank says 6 amps
I find that kinda hard to believe especially when it’s on a 20 amp breaker
When it cuts on I can tell by the sound of the generator it’s drawing some amps
I’m no electrician that’s why I’m asking you guys

 

[The Cobbler]

a motor at start up uses far more amps than when it's running.

 

[wyliesdiesels]

How many amps does a 230 volt 1/2hp well pump draw
The tag on the pressure tank says 6 amps
I find that kinda hard to believe especially when it’s on a 20 amp breaker
When it cuts on I can tell by the sound of the generator it’s drawing some amps
I’m no electrician that’s why I’m asking you guys

you sure its 1/2 hp?

NEC table FLC lists 1/2hp as 4.9a, which is always higher than nameplate FLA.

also, motors have in-rush currents which are 4x-8x nameplate FLA.... they draw a lot more current on startup

Is there an issue?

 

[Hot shot]

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[wyliesdiesels]

I cant read that. Resolution is too low

 

[Hot shot]

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[Hot shot]

I know starting watts is more
I guess u need an amp meter for that
I’m getting all my amperage numbers so I know what I can run off of generator
I’m having to toggle things off and on so I don’t overload the generator

 

[wyliesdiesels]

Youve got 2 different motor stickers there.

which brand is in the well?

or those may be old and it may be something else

but for a motor, you need to consider the inrush current as well, because while you generator running watts may be able to handle the load, it may not be able to handle it when the pump is starting

also notice the SF is pretty high.... this can change the FLA

 

[Hot shot]

Myers tank
Franklin pump
That’s what was here when I bought the house
I guess because of the surge is why it’s on a 20 breaker

 

[wyliesdiesels]

yes the breaker needs to be sized large enough to compensate for the inrush current

 

[Hot shot]

Here’s why I have to toggle things on and off
6 amp fridge
5 amp upright freezer
1500 watt toaster oven
1100 watt microwave
Coffee maker??
2 1500 watt delonghi oil filled radiators for 2 bedrooms gas logs do the living room
Dishwasher 12 amps Haven’t run that since power outage
Well pump
Water heater
Septic pump don’t know what that draws. It’s on a single pole 20
Wonder if the 12 amps on dishwasher is pump motor and heat element combined amperage

 

[Captain Spaulding]

Just because a motor works on a 20A breaker doesn’t mean it will work on a generator, even if the generator is rated for the same power as the breaker can pass. The generator has a surge rating and a continuous rating. Generally the surge rating is the absolute maximum the generator can provide. A 20A household circuit could potentially source 100A for the very brief period it takes the motor to spin up.

 

[Metal-Marc]

As per the nameplate: KVA Code R

Locked Rotor Amp, which is around 18A @ 240V

That should be your startup current.

https://instrumentationforum.com/t/locked-rotor-current-of-a-motor/8290

As per the nameplate, the running current is 5 A

 

[u3b3rg33k]

What generator do you have? assuming a "typical" 4kW/8hp generator with a 20A 220V 2x 120V 20A breakers, yes, you will have to manage your loads. technically, the space heaters would come close to maxing that out on their own (12A each on high /3kW), and should be on opposite sides of the generator spit phase.

toaster/microwave only use power while in use, so that's easy. use one at a time. coffee maker: it depends.

 

[wyliesdiesels]

As per the nameplate: KVA Code R

Locked Rotor Amp, which is around 18A @ 240V

That should be your startup current.

https://instrumentationforum.com/t/locked-rotor-current-of-a-motor/8290

As per the nameplate, the running current is 5 A

with your reference it would be 16.83a - 19.22a

 

[Hot shot]

What generator do you have? assuming a "typical" 4kW/8hp generator with a 20A 220V 2x 120V 20A breakers, yes, you will have to manage your loads. technically, the space heaters would come close to maxing that out on their own (12A each on high /3kW), and should be on opposite sides of the generator spit phase.

toaster/microwave only use power while in use, so that's easy. use one at a time. coffee maker: it depends.

Could you explain how the split phase works
I have an idea
Is it evening out the load
I’m trying to learn all I can about this stuff

 

[Hot shot]

It’s a 5250/7350
13hp
30 amp

 

[wyliesdiesels]

Could you explain how the split phase works
I have an idea
Is it evening out the load
I’m trying to learn all I can about this stuff

Split phase is 120/240. 2 hots and a neutral that is tapped in the middle of the secondary winding. Thus its called split phase

You want to balance the load as evenly as possible on the 2 phase legs of your generator

 

[Hot shot]

And how do I do that

 

[dave*99]

And how do I do that

I could give you the full engineering explanation - but instead I will give you a practical example.

Lets say you have 2 separate duplex receptacles on your generator - remember a duplex receptacle can receive 2 plugs. So lets call those duplex receptacles A and B.

You want to split up your appliance loads evenly on A and B.

So if you have (2) space heaters and they each consume 1500W, you want to put 1 heater on A and 1 on B.

Following that example - add up the consumption of your appliances and distribute them to A and B evenly.

 

[Hot shot]

Gotcha
Yea I’m not using any of those
I’m using the 30 amp plug on the generator
Back feeding to the main panel in the house
Thanks for clarifying that up

 

[Lightning rod]

actually , the 30a (assume 240v) plug on the generator still connects back to the same place (windings)that the outlets connect to.

what model /make of generator do you have?
the owners manual has the wiring connections and you can confirm some things

if the 30 plug connects back to the main panel as a 120/240v connection, load balancing is still required. as previously explained

 

[wyliesdiesels]

Gotcha
Yea I’m not using any of those
I’m using the 30 amp plug on the generator
Back feeding to the main panel in the house
Thanks for clarifying that up

doesnt matter what method you use to connect to the generator. the principle is the same. that 30a 120/240 outlet, has 2 legs that need to have equal load on them

since this will be connected to a panel, you need to balance the circuit breakers across the 2 phases in the panel

And hopefully you are using an interlock or transfer switch to lock out the utility power from the generator power.

 

[Hot shot]

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[Hot shot]

30 amp plug
Why does it say 43-21 amps

 

[dave*99]

30 amp plug
Why does it say 43-21 amps

Generator can supply 21 amps at 240 volts or 43 amps at 120 volts
And watts = volts X amps.
Generators are rated in watts.
Your loads may be 120, 240 volts
You get to do the math based on your loads.

You use a 30A cord set and connectors because your generator can supply 21A at 240V so the cord set is sufficient.

 

[dave*99]

Gotcha
Yea I’m not using any of those
I’m using the 30 amp plug on the generator
Back feeding to the main panel in the house
Thanks for clarifying that up

Since you are feeding the main panel it’s a little harder to determine how your loads hit the main panel compared to plugging in to receptacles. Ultimately your main panel has 2 legs that are connected like the examples I gave as receptacle A and B.
Half of your breakers are on A and half on B
The 240 loads are across A and B.

 

[Hot shot]

The other thing is I have POWER!! After 6 1/2 days
Power company cut it on and it blew a 100 amp fuse on the pole near the transformer
They drove up and down the road looking at the wires, didn’t see anything. Put another fuse in and blew it too. Guy said it was something small doing it
They went back up the road looking at stuff. They either found the problem or got lucky on the 3rd try because it never blew again

 

[Hot shot]

Dave thanks for the info
Makes sense to me

 

[Lightning rod]

go to this parts site and print out the wiring diagram
https://www.jackssmallengines.com/j...5-250-watt/1971-0-5-250-watt/wiring-schematic
it will help you understand the connections
also , this guy repairs generators and will

give you insight into repairs

 

[Hot shot]

I will do that thanks