a question about relays

[B Ghostleader]

I have a project that I would like to control two relays with one
swiich. Is this possible? I was going to use a DPDT relay but that
price is a little steap for the current rating that a I needed(25 amps
min). I can go down to the local automotive store a get a 30 amp relay
for 5 bucks.

 

[Larry Brasfield]

I have a project that I would like to control two relays with one
swiich. Is this possible? I was going to use a DPDT relay but that
price is a little steap for the current rating that a I needed(25 amps
min). I can go down to the local automotive store a get a 30 amp relay
for 5 bucks.

The problem you will have, if you do that, is that
only one relay will actually do the work of breaking
the current. The other will open first, with little wear
on its contacts. Then the other will open, and have
to break more than its rated current to do so. One
result will be faster contact wear. Another result
could be failure to break the circuit at all, depending
on the voltage, or contacts welding together.

 

[John Fields]

The problem you will have, if you do that, is that
only one relay will actually do the work of breaking
the current. The other will open first, with little wear
on its contacts. Then the other will open, and have
to break more than its rated current to do so. One
result will be faster contact wear. Another result
could be failure to break the circuit at all, depending
on the voltage, or contacts welding together.

 

[John Fields]

I have a project that I would like to control two relays with one
swiich. Is this possible? I was going to use a DPDT relay but that
price is a little steap for the current rating that a I needed(25 amps
min). I can go down to the local automotive store a get a 30 amp relay
for 5 bucks.