wiring relays in parallel to increase load capacity

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Jun 18, 2011 | 01:41 AM

#16

5-90

CF Veteran

Joined: May 2008

Posts: 3,018

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Year: 1988

Model: Cherokee

Engine: AMC242

Quote:

Originally Posted by ericfx1984

nothing now... I found a fan that works fine and only needs around 30 amps...

also I found that if you use the Taurus 3.8 dual speed fan it CAN pull up to 70 amps , but that is only from a dead stop going straight to HIGH SPEED...

if you run 2 thermo switches with one 30 amp relay per thermo switch and make sure that the low speed (2500CFM) is turning before the HIGH SPEED (4500CFM) kicks on, then the fan will not pull nearly as many amps during HIGH SPEED spin up

BUT... like I said, I am using a Taurus 3.0 fan instead of the 3.8, it is smaller and a simple drop in, for the most part... that in conjunction with the stock A/C fan and I NEVER over heat...

30A isn't a strain for a full-size DIN relay - they're commonly rated for 30A (NO contacts)/15A (NC contacts,) and quality units - like the ones I carry - are rated for 40A (NO)/20A (NC.)

- NO (Normally Open.) Contacts that are typically connected to the circuit to be turned ON when the relay is powered.
- NC (Normally Closed.) These contacts will turn a circuit OFF if the relay is powered. This circuit is optional on the DIN relay - many have only four prongs, and lack this circuit.

Mini-DIN and Micro-DIN relays will burn out, and I can source DIN relays up to around 70A - I just haven't had enough demand to keep them around yet...