Garbage disposal wiring problem

[Elton Smith]

I bought a garbage disposal and had it installed under the sink by a plumber. When we attach it to the power, if the switch is turned on the disposal runs. When the switch is turned off, it trips the circuit breaker. I tried attaching a different switch, but it still has the problem. The clothes washer is plugged into this same circuit and works fine.

 

[Megawatt]

I bought a garbage disposal and had it installed under the sink by a plumber. When we attach it to the power, if the switch is turned on the disposal runs. When the switch is turned off, it trips the circuit breaker. I tried attaching a different switch, but it still has the problem. The clothes washer is plugged into this same circuit and works fine.

Eleton who did the wiring on the garage disposal?

 

[Elton Smith]

Eleton who did the wiring on the garage disposal?

It was done by the plumber.

 

[Megawatt]

It was done by the plumber.

It sounds strange usually the breaker trips when turned on not off. Did he get the power from the light switch only

 

[Marvo]

Is it tripping the RCD or just the circuit breaker that protects that circuit?

If it's the RCD then first step is to megger test the waste disposal and ramp test the RCD. Both these tests need special testers so you'll need to get a sparky.

 

[Megawatt]

Is it tripping the RCD or just the circuit breaker that protects that circuit?

If it's the RCD then first step is to megger test the waste disposal and ramp test the RCD. Both these tests need special testers so you'll need to get a sparky.

It sounds strange usually the breaker trips when turned on not off. Did he get the power from the light switch only

@Marvo it’s the 20amp breaker feeding the kitchen and what’s so strange is the breaker don’t trip till he turns off the breaker. He hasn’t replied back so I can help him, plumbers shouldn’t do electrical

 

[Elton Smith]

It's a 30 amp breaker in the laundry room. The folks downstairs have a partial kitchen with a sink in the laundry room. That's where we are putting the garbage disposal.
I looked up RCD. Not sure if we have this. It's a 40 year old circuit box for the house.
My theory is that I may have bought a bad garbage disposal. I'm looking up what a megger test is.

 

[telectrix]

our name RCD is what you would call a GLFI, or something like that. megger test is the old name for insulation resistance test, so called because you had a megger instrument ( wind up) to test.

 

[Devonchris]

Sounds like it's an RCD and a DP switch with a slight delay between the poles.

 

[Megawatt]

It's a 30 amp breaker in the laundry room. The folks downstairs have a partial kitchen with a sink in the laundry room. That's where we are putting the garbage disposal.
I looked up RCD. Not sure if we have this. It's a 40 year old circuit box for the house.
My theory is that I may have bought a bad garbage disposal. I'm looking up what a megger test is.

our name RCD is what you would call a GLFI, or something like that. megger test is the old name for insulation resistance test, so called because you had a megger instrument ( wind up) to test.

our name RCD is what you would call a GLFI, or something like that. megger test is the old name for insulation resistance test, so called because you had a megger instrument ( wind up) to test.

telectrix it’s GFCI in the Us

our name RCD is what you would call a GLFI, or something like that. megger test is the old name for insulation resistance test, so called because you had a megger instrument ( wind up) to test.

It's a 30 amp breaker in the laundry room. The folks downstairs have a partial kitchen with a sink in the laundry room. That's where we are putting the garbage disposal.
I looked up RCD. Not sure if we have this. It's a 40 year old circuit box for the house.
My theory is that I may have bought a bad garbage disposal. I'm looking up what a megger test is.

our name RCD is what you would call a GLFI, or something like that. megger test is the old name for insulation resistance test, so called because you had a megger instrument ( wind up) to test.
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It was done by the plumber.

@elton could you send some pictures of the wiring on the garbage disposal and light switch. Don’t bother megging it we already know that it’s going to ground and tripping the

 

[Megawatt]

telectrix it’s GFCI in the Us

Elton could you send us pictures of the garbage disposal wiring and also the switch wiring. Don’t bother megging it we already know that it’s going to ground

 

[Devonchris]

Don’t bother megging it we already know that it’s going to ground

How do you know that?

If it is (going to ground) then how come it holds until switched off?

 

[Megawatt]

How do you know that?

If it is (going to ground) then how come it holds until switched off?

Devon that’s what I’m trying to figure out. You and I both know that 99% of the time when it’s turned on is when the breaker trips not the other way around. I know something funky is going on and we can debate this all night or get pictures to help the OP
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It's a 30 amp breaker in the laundry room. The folks downstairs have a partial kitchen with a sink in the laundry room. That's where we are putting the garbage disposal.
I looked up RCD. Not sure if we have this. It's a 40 year old circuit box for the house.
My theory is that I may have bought a bad garbage disposal. I'm looking up what a megger test is.

@elton here’s what I’m thinking is going on the plumber used a 3 way switch he has terminated the hot to the common screw, terminated the garbage disposal to the NC contacts of the switch when it’s turned on and terminated the neutral to the NO screw. When he turns it off the NO contact closes and trips the breaker

 

[DPG]

Megawatt's theory sounds good to me.

Edit: my posts still won't show unless cleared by a moderator. What's going on?

 

[Megawatt]

Megawatt's theory sounds good to me.

Edit: my posts still won't show unless cleared by a moderator. What's going on?

@DPG it’s all good it just took me a while to figure it out and he didn’t send no pictures