Can the same relay come in different sizes?
08-10-2001, 12:23 PM
#1
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Can the same relay come in different sizes?
Last night I purchased a radiator fan relay from Auto zone. It is a GP Sorensen. The relay, however, appear to be half the size in length as that of the one installed. Can relays be different sizes? How do you remove a relay? Thanks -
Jeremy
1983 Guards Red
Jeremy
1983 Guards Red
08-10-2001, 01:35 PM
#3
Nordschleife Master
Make sure the electrical posts are the same, but yes, relays can be different sized. I assume you mean the new one is shorter not 1/2 the "length" or base footprint that plugs into the connector.
To remove the old one you just pull up on it. Sometimes the connectors grab onto the relay posts pretty tight so just rock it back and forth and pull up. If you are throwing the old one away you could just grab the top with a pliers go get a better grip.
To remove the old one you just pull up on it. Sometimes the connectors grab onto the relay posts pretty tight so just rock it back and forth and pull up. If you are throwing the old one away you could just grab the top with a pliers go get a better grip.
08-10-2001, 02:10 PM
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Jeremy... "Relays 101"... a relay is just a switch, operated by electricity. It does the same thing as any other switch, but does it when you apply or remove an electrical signal, instead of a finger. In this case it allows a low amperage 12VDC circuit to turn on/off a higher amperage 12VDC circuit.
In the case, you'll find two main things:
A) There's a coil that creates the magnetic field that provides the force (substitute for your finger on wall switch). This is what the low amperage circuit operates (it's the "load" for that circuit), and it's what makes the contacts (see "B" below) open / close.
B) There are contacts that are closed or opened by the force of the magnetic field, same as the contacts in a wall light switch. These either complete a circuit ('on')or break a circuit ('off').
Add a spring to return the contacts to their previous position when the coil is turned off, and you've got it.
The pins on the relay are for A) providing connection (hot & ground) to the relay to turn it "on and off", and B) connections to the contacts (power in & out to load [whatever is being powered thru the relay]).
Four things will tell you if a relay will substitute for another relay:
A) Is the coil voltage the same? (we're talking 12VDC here; no problem).
B) Are the contacts big enough to handle the load? This is harder to judge, but if the contacts burn out or fuse together, they weren't
.
C) Are contacts the same arrangement of open / closed? They're labelled by their position when power is off to the coil: "normally open" & "normally closed"; these states will reverse when you apply power to the relay.
D) Is the male pin arrangement on the bottom the same as the female socket it has to go into? Not recommended, but you can jumper this with wire if it's the only problem; risks a short circuit, tho'.
I just finished troubleshooting & fixing a student project where a computer output signal turns on a 5VDC (coil) relay that turns on a 24VDC (coil) relay, which turns on a 120VAC (coil) relay, which closes a 480VAC line...thus, a computer "turns on" a three-phase 480V conveyor motor.
Sorry for being so wordy... a chalkboard and hand-waving helps...
Jim, outta here!!!
In the case, you'll find two main things:
A) There's a coil that creates the magnetic field that provides the force (substitute for your finger on wall switch). This is what the low amperage circuit operates (it's the "load" for that circuit), and it's what makes the contacts (see "B" below) open / close.
B) There are contacts that are closed or opened by the force of the magnetic field, same as the contacts in a wall light switch. These either complete a circuit ('on')or break a circuit ('off').
Add a spring to return the contacts to their previous position when the coil is turned off, and you've got it.
The pins on the relay are for A) providing connection (hot & ground) to the relay to turn it "on and off", and B) connections to the contacts (power in & out to load [whatever is being powered thru the relay]).
Four things will tell you if a relay will substitute for another relay:
A) Is the coil voltage the same? (we're talking 12VDC here; no problem).
B) Are the contacts big enough to handle the load? This is harder to judge, but if the contacts burn out or fuse together, they weren't
.C) Are contacts the same arrangement of open / closed? They're labelled by their position when power is off to the coil: "normally open" & "normally closed"; these states will reverse when you apply power to the relay.
D) Is the male pin arrangement on the bottom the same as the female socket it has to go into? Not recommended, but you can jumper this with wire if it's the only problem; risks a short circuit, tho'.
I just finished troubleshooting & fixing a student project where a computer output signal turns on a 5VDC (coil) relay that turns on a 24VDC (coil) relay, which turns on a 120VAC (coil) relay, which closes a 480VAC line...thus, a computer "turns on" a three-phase 480V conveyor motor.
Sorry for being so wordy... a chalkboard and hand-waving helps...
Jim, outta here!!!
