# What is terminal 85 on a relay?

## What is terminal 85 on a relay?

Terminal 85 grounds the electromagnet. Terminal 30 supplies power to one of the internal switch contacts. Terminal 87 connects the other internal switch contact to the device controlled by the relay.

## What is pin 87 on a relay?

Numbers of a Relay Note that each pin is numbered. 85 and 86 are the coil pins while 30, 87, and 87a are the switch pins. 87 and 87a are the two contacts to which 30 will connect. If the coil is not activated, 30 will always be connected to 87a. Think of this as the relay in the Normally Closed (OFF) position.

Which terminal is ground on a relay?

Understanding Relays, part 2: DIN numbers and different types of relay

Terminal Which Circuit? Definition
86 Low current (control) Relay coil + (power input)
85 Low current (control) Relay coil – (ground)
30 High current (load) From battery +
87 High current (load) Output to device, normally open, pulled closed when coil is energized

### What are micro relays?

A micro relay is a smaller version of the more popular standard relay and are used when space is at a premium. Note, a standard relay is also sometimes referred to as a ‘Mini Relay’.

### What is the difference between Terminal 87 and 30 on a relay?

Two circuits (terminals 87 and 87a ) have a common terminal (30). When the relay is at rest 87a is connected to 30, and when the relay is energised 87 becomes connected to 30 (but never both at the same time). Terminal 87 is linked to pin number 87b, giving double outputs from the single NO contact.

How do you describe a relay circuit using terminal numbers?

We can now describe the relay circuit in the figure above using the DIN terminal numbers: When the external switch is thrown, terminal 86 receives 12 volts. Since terminal 85 is connected to ground, this causes current to flow through the coil in the electromagnet, which pulls the two internal switch contacts (30 and 87) together.

#### What is the size of a 4 pin relay terminal?

Terminal sizes The terminal widths used on 4 and 5 pin relays are almost always 6.3mm wide, however some more specialist relays can have terminal widths of 2.8mm, 4.8mm and 9.5mm.

#### What terminal does the changeover relay connect to?

Changeover relay. Two circuits (terminals 87 and 87a ) have a common terminal (30). When the relay is at rest 87a is connected to 30, and when the relay is energised 87 becomes connected to 30 (but never both at the same time).