Went to local autojumble this morning and bought a big bag [50odd for a quid!] of 12v relays, my intention was to use one for a cooling fan, I asked a question regarding a wiring diagram for the fan relay and a diagram was posted up, however the relay used in that reply had 4 connections numbered 86,87 85, & 30, the connections on the relays I bought today are numbered 1-5??? what is the relevance of numbers 85,86,87 and 30,??
and can i use the realys i bought for the fan?

ISO Relay

Contact arrangement for the ISO and Super ISO relays
The ISO relay has rather oddly numbered contacts, the system having been carried-over from the original German DIN specification. Each contact is 6.35 mm (1/8") wide and 11 mm (7/16") long.
Note that, while it is electrically irrelevant which way round the coil is connected, it is usual to make contact 85 electrically closest to ground.
Keeping to this convention helps others who may in future have to diagnose any problems.

Always mount relays with the contacts pointing down, this attitude prevents water build-up between contacts.

85 Coil Low

86 Coil High

87 NO contact

87A NC contact

30* Common

* Contact 30 is sometimes marked 30/51.



[Edited on 26/2/05 by Snuggs]