Power relay NO but coil always energized

I have a question about a relay. I need a solid state relay that will work like the mechanical one pictured. The situation is this:

The coil will remain energized constantly (8 hours a day) with 5.5 VDC (i want an amperage of about 20mA) across contact positions 85 & 86, except that momentarily the voltage will go to zero, at which point the switch will “close” to connect positions 30 & 87A.

When closed, the output current is 4 amps @ 24DC

Is it possible to do this with a relay (I think solid state) that will survive being energized this long?

Cost is not an object for the relay.

Good day @tierson,

If you were to drive for 8 hours in your car, that very relay could be energized the entire time. No worries unless the datasheet for a mechanical relay indicates it has an issue with being energized perpetually.

We do not carry many ‘normally closed’ solid state relays(SSRs). I did find this one CC1591-ND, but it’s not cheap. Also, it is only rated for 5A. Do you have any inrush concerns with your load?

SSRs use an LED inside, so no worries about being on for 8 hours (or all week). They eventually do dim over time, but you would be many years out before that is a concern.

A mechanical would work, but you’d need to have more than 20mA available to drive the coil.

Hope this helps,


Thank you for your thoughtful response. When I look at this data sheet, how do I know that it is normally closed?

5 amps is enough, it’s a max 3.6 amp load.

Is an inrush concern the same as a peak load?

The coil amperage could be higher, probably as high as 100ma

I would also add, the current spec for relay , you may want to check to see if your load is in inductive or resistive, as I think you are eluding to in your recent comment.


You are correct, the datasheet could be more clear(on page 5) as to what the ‘-B’ indicates. I was going off of our search parameters.

On page 6…

These would only make sense if the load was turning on as the control voltage is removed, so it should confidently be a normally closed relay.

It looks like the DC60S5-B can handle a 10A inrush/peak/surge current for 10mSeconds.

If you have up to 100mA for the coil, the G2R-1-S DC6(S) should be a viable option. Coil is rated for 6V, but says it will turn on by 4.2V, so 5.5V should work fine.

The load is a solenoid, that means indicative?

That is correct. Solenoids are inductive loads, which needs to be factored in because inductive loads like motors and solenoids are much harder on a mechanical relay than a load that is purely resistive for example.

Thank you. I ended up ordering a 10 amp mechanical power relay and I hope that one will be ok with an inductive load. The relay I ordered was:


‎G2R-1-S DC6(S)‎


I will wire it to be normally closed.

The coil voltage will be 6V. The output voltage is 24V.

The coil amperage can be as high as 2 amps, this relay will only draw .3 amps.

The contact amperage is 10 amps, the load is 3.6 amps inductive load.

Will I be ok, or should I add some protection?

I think you will be good.

3.6 amps for a solenoid could mean quite a bit more for inrush

We do carry Inrush Current Limiters

…they drop in resistance as they self-heat. Figuring out which one might serve best can be interesting…

Or- this is a 15A Dual Pole relay. You could tie the two poles to operate in parallel to each take 1/2 the load.