Best Answer

A relay is an electrically actuated switch. There are a number of contacts actuated by a soleniod. When the solenoid is energized the position of the contacts changes, "throwing" the switch. The terminology of switches and relay contacts is as such: (number)p-(st(no/nc)/dt) The number followed by p is the number of poles. This is the number of independent "switches" in the unit. The (number)p may be replaced with sp (single pole) meaning 1p or dp (double pole) meaning 2p. ST stands for single throw, there is only two contacts for each pole. ST is usually suffixed with NO or NC in relays standing for normally open and normally closed. Normally open contacts conduct when the solenoid is energized. Normally closed contacts conduct when the soleniod if off. DT stands for double throw, meaning that there are 3 contacts per pole: a common contact, a NO contact, and a NC contact. So: a 3p-st NO relay has 3 switches that close when energized. a sp-dt relay has one 3 contact switch. An electrically actuated 3-way switch, if you will. a dp-st NC relay has one switch that opens when the solenid is energized.

User Avatar

Wiki User

โˆ™ 2007-06-03 23:37:40
This answer is:
User Avatar

Add your answer:

Earn +20 pts
Q: What does a relay do?
Write your answer...
Related questions

Where is the fan relay?

The fan relay is in the relay box next to the says fan relay on it.

What is auxiliary relay?

An auxiliary relay is a back-up relay in case the primary relay fails.

What is pick up of a relay?

The "pick up" of a relay is a setting at which the relay will begin to operate. Such as an overcurrent relay - if the pickup is set to 5A, when 5A is flowing through the relay, the relay will operate.

Which relay is the starter relay on a 1994 Buick lesabre?

Which relay is the starter relay on a 1994 buick lesabre

Where is the relay switch on a 2002 Chevy Cavalier?

THE relay switch? Which one? The Light relay, AC relay? Turn signal relay? Be more specific.

What is function of mho relay?

OFFSET IMPEDANCE RELAYOffset impedance relay is also known under names ADMITTANCE RELAY or MHO RELAY

How many people swim in a relay team?

It depends what relay you mean - a normal relay has four swimmers (e.g. an IM relay or a freestyle relay) bu relays such as a cannon relay can have more

How to find out if a relay is bad?

Swap relay with another like relay.

Inhibitor relay location 1990 Nissan Stanza?

the inhibitor relay is between the a/c relay and the cornering relay

What is the difference between a relay and an auxiliary relay from constructionapplication poin of view?

I think aux relay is part of relay

Earth fault relay and an overcurrent relay Methods to energise an earth fault relay?

Earth fault relay and an over current relay Methods to energies an earth fault relay with simulation diagram?

How do you find out what the bottom 3 fusses do on the kick plate of a 94 Toyota pick up?

one is the circuit opening relay one is the circuit opening relay one is the circuit opening relay one is the circuit opening relay one is the circuit opening relay one is the circuit opening relay one is the circuit opening relay one is the circuit opening relay one is the circuit opening relay one is the circuit opening relay one is the circuit opening relay one is the circuit opening relay one is the circuit opening relay

What is the relay located with the fuel pump relay on a 1991 S10 blazer?

That other relay should be the AC compressor relay.

What is the relay next to the glow plug relay?

air charge resistor relay

What is cdg relay?

cdg is circular disk gear relay which is electromagnetic relay

What are the symptoms of a bad fuel pump relay?

The main relay and the fuel pump relay are the same. Take the fuel pump relay and swap it with the main relay and see if that will help you....

What the Generator lockout relay?

generator lockout relay is a relay that the output of other relays energize this relay and its out put use for tripping of generator. this relay must be reset manually

What is translay RELAY?

translay relay

Where is the fuel pump relay on a 99 mercury sable?

The relay is in the fuse/relay box under the hood it is relay number 29

Will a bad relay prevent a dodge ram 1500 from starting?

Depends on which relay, some can. The asd relay can, the wiper relay can't.

Where is the cruise relay located 2004 DODGE 2500?

The cruise system does not have a relay.The cruise system does not have a relay.

Does a 1995 Mazda 2300 pickup have a fuel pump relay?

The relay is located under the hood in the relay bank on the drivers side of the engine. FYI the relay is the same as a headlight relay...which is cheaper than a fuel pump relay.

How to wire a relay?

Follow the schematic of the relay. A relay is simply an electrical switch that is operated by an electric current. When current is present at the relay coil, the relay toggles the switch. If you do not know how to read the schematic of a relay, you probably shouldn't be messing with it.

What is a relay in power plants?

A relay in power plants comprises three components namely voltage relay, thermal relay and current relay. It is used to power up an industrial equipment.

Were is the ac relay 1987 Ford Ranger?

It is the black relay mounted to the passenger side fender wall, not to be confused with the green relay, which is the fuel pump, or the brown relay, which is the computer relay