Do I need a bigger amp relay or a better quality?

[sofasurfer]

I have a cheap winch on my truck bed. The motor is 40 amps. I have a 40 amp circuit breaker. The relays in the winch control box are 40 amp. They keep burning the point and sticking. The also have excessive up and down movement. The relays are Liming LR4190-DC12V-1C 40 amp/14DC. The cost about $7 each. My question is, to stop the burning do I need a higher amp relay or a better quality? How to you determine if a relay is a better quality?

 

[Wrench97]

You probably need continuous duty solenoids, motors draw a higher current(inrush) when starting and that is probably what is damaging the relays, once they start getting black and pitted the poor connection causes voltage drop and higher amp draws.

 

[nadogail]

Sounds like a job that could be handled by "Starter Solenoids".

 

[sofasurfer]

This is the winch. Need the little relays that will fit in the box. https://www.harborfreight.com/reviews/write?reviewsku=95912

 

[RPH]

Two things come to mind. One is revered to as machine gunning the buttons. That is the constant on / off of the button. This causes the relay to make and break over and over. With a large inductive load arcing is induced into the contacts. They die.
Two, is duty cycle. It’s not just the motor that has a duty cycle but other components have too. Contacts in a heavy relay will have a duty rating. Check to be sure you’re within parameters on both counts.

 

[The Cobbler]

those relays look very light for a 40 amp motor load in my opinion

 

[sofasurfer]

The relays ARE rated at 40 amp.

 

[The Cobbler]

what is the running amps and the inrush amps of the motor ?

 

[sofasurfer]

I have no way of knowing those specs. If you look at the link in first post you see that this a a cheap harbor freight winch.

 

[walta]

I think if you do a search for “12V winch relay” you will find they are generally rated for over 250 Amps and Amazon will deliver it for about $23

Walta

 

[The Cobbler]

you came on with a question, people are trying to help.
I think the problem is the relays are too small , even the fact thats how it came .
again, they look very small for a motor of that size . and the fact hey keep burning out emphasizes that .

 

[The Cobbler]

I googled " winch relays" and here's what came . they are all much physically larger & higher rated than yours is

 

[alfredeneuman]

Sounds like a job that could be handled by "Starter Solenoids".

A starter solenoid is made for occasional use. The starter wouldn't be running all the time. Continuous duty relays are made that look like early Ford starter relays.

Amazon.com

 

[dogdog]

Dunno how your relays are configured, or if it is used in a way to reverse your winch motor what nots.

If it is not used in reversing configurations. You might want to look up how to put a snubber for your relay coil. And see what fits your situation.


This is just an example… you will still have to see what fits your need.

Snubber Circuits for Protecting Relay Contacts from Arcing – Making Easy Circuits

makingcircuits.com

 

[MBfreak]

RPH explains the problem with inductive loads. Perfect.
You may try bridging each relay contact with a 1µF 100 V high quality capacitor to reduce the arcing at
switch off.

Ola

 

[BillK]

If you want to keep the same exact configuration I would get a higher amperage relay. This one is rated at 60/80 amps:

https://www.etrailer.com/Accessories-and-Parts/Bulldog-Winch/BDW20101.html?feed=npn

 

[LukeOresk]

Your relays need to be hp rated if they are controlling the winch. Amp rating doesn’t account for the motor starting current that will toast the contacts of not motor rated equipment

 

[alfredeneuman]

Your relays need to be hp rated if they are controlling the winch. Amp rating doesn’t account for the motor starting current that will toast the contacts of not motor rated equipment

There's no requirement for being HP rated. That is an NEC requirement which is not applicable to this situation.
The relay that I linked to says "Golf Carts Heavy Duty Winch Marine IN RUSH".
It accounts for starting current. Do you think that there is no increased starting current for golf cart motors?

 

[LukeOresk]

There's no requirement for being HP rated. That is an NEC requirement which is not applicable to this situation.
The relay that I linked to says "Golf Carts Heavy Duty Winch Marine IN RUSH".
It accounts for starting current. Do you think that there is no increased starting current for golf cart motors?

No that’s why I said they have to be hp rated. They have to be able to handle the starting current of the motor.

I never really work with 12v dc but in rush or motor rated or heavy duty or whatever they want to call it is needed in this situation.

 

[alfredeneuman]

The horsepower rating refers to a specific thing in the NEC.
It's applied to switches, receptacles, contactors, and disconnects.

 

[LukeOresk]

The horsepower rating refers to a specific thing in the NEC.
It's applied to switches, receptacles, contactors, and disconnects.

I was unaware that automotive doesn’t use that term. I guess that makes sense since automotive isn’t covered by your country’s electrical code or mine.

I learned something, now I need to understand how automotive defines its ratings