Air pressure switch and transformers

[msearcher]

Is there any difference between using one off of a model 22 on a 41?

thanks for any advice as they appear to be exchangeable.

[hawkins111]

Transformers are the same. Air Pressure switches are different. The switch for the M41 is much bigger and must trip at a different pressure. Tom

[msearcher]

Transformers are the same. Air Pressure switches are different. The switch for the M41 is much bigger and must trip at a different pressure. Tom

Thank you Tom, any way to tell a 422 from a 441 or a 22 from a 41 air pressure switch as they can look the same.

Tom

[hawkins111]

The M441 and M41 air pressure switch is much larger than the 21, 422. I believe the M441 and M41 are round where the M21 and 422 are square and much smaller. Tom

[msearcher]

Tom

i have a 22 with the large round air switch like the 41 and also a 441's with both the large and later ones with the smaller square.

tom

[hawkins111]

The M22 with a large round air switch has an incorrect switch on it. Not saying it does not work, just that it is the wrong part. The M441 can have both a large and a small switch on it. I do not know when the change occurred. My M441 was made in 1996 and it has a small switch. The book has different part numbers for M22 and M41 , and M422 and M441. In all cases I have looked into when Monitor assigned a different part number, the part is different.

[msearcher]

The M22 with a large round air switch has an incorrect switch on it. Not saying it does not work, just that it is the wrong part. The M441 can have both a large and a small switch on it. I do not know when the change occurred. My M441 was made in 1996 and it has a small switch. The book has different part numbers for M22 and M41 , and M422 and M441. In all cases I have looked into when Monitor assigned a different part number, the part is different.

Thank you for your response.