What does 87a mean 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.
Can you use a 5 pin relay as a 4 pin?
Some 5 pin relays are SPDT (switch between the two pins) and some are DPST (like the main relay- connect 2 pins at the same time.) If you want to use a 5 pin in place of a 4 pin, you shouldn’t have to remove the pin. The socket should be the same, but the center pin won’t have a contact in it.
What happens if you put a relay in backwards?
Many relays, if installed for the wrong application, could and will cause a short (Internal Relay Circuit) and most likely cause functionality issues or even damage to the vehicle computer systems.
How to tell if a relay is 87A or NC?
Be careful when buying replacement relays as well–some of the ones they sell for lighting setups appear the same (have all 5 terminals), but there are really just 2 87 pins, no 87A I don’t know what NC is, but 87a is energized when the power source is not present.
What is the difference between a 87a and a 5-pin relay?
Thanks for your clarification. Some “5-pin” relays are dual-output types with two 87 terminals. (Warning – some relays like Hansa have them incorrectly labelled as 87 & 87a.) With two connected terminals they’d both be 87, with isolated, 87b.
What does 87A mean on a circuit breaker?
A very high resistance or open circuit reading can indicate a damaged coil. The numbers 85, 86, 30, 87 & 87a (or other numbers for different relay configurations) are normally moulded into the plastic next to each pin and also shown on the circuit schematic.
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.