Relay Question - SSR vs. others

[Kit_B]

Can anyone tell me whether I can use this:

http://www.grainger.com/product/SCHNEIDER-ELECTRIC-Enclosed-Power-Relay-1DPP6

...In the place of a pair of SSRs, for switching a 4500 watt heating element with a 12vdc output?

Would it function correctly?
Would it wear out faster?
Thoughts on temperature?

Thanks, in advance.

 

[Kit_B]

Here's a little more information, about the relay in my question:

Here

 

[helibrewer]

Seems to have good specs for a mechanical relay. The data sheet indicates that it can do everything needed for controlling an element.

 

[Brumateur]

That relay can control 4500 Watt heater.
However you can't connect it to PID SSR output directly. The relay coil require more current than PID can provide. You need to use either PID with relay output plus external 12 volt power supply or use some electronic circuit to control relay. Again you will need an external 12V power supply.

And mechanical relay have a longivity issue whe working with a PID. Iven if you set duty cicly time 5 sec (instead of regular 2 sec) that relay will last about 150 hours.

 

[Kit_B]

That relay can control 4500 Watt heater.
However you can't connect it to PID SSR output directly. The relay coil require more current than PID can provide. You need to use either PID with relay output plus external 12 volt power supply or use some electronic circuit to control relay. Again you will need an external 12V power supply.

And mechanical relay have a longivity issue whe working with a PID. Iven if you set duty cicly time 5 sec (instead of regular 2 sec) that relay will last about 150 hours.

If I decide to use it, it will be with a Brewtroller & 12vdc power supply.
(Side note: Some PIDs actually do put out 12vdc to an SSR... Like this one that I own)

The cycle time & longevity may be an issue. I'm not fully convinced that this is the way to go, but I have a feeling it may run cooler than 2 SSRs & I'm running out of space needed for a large heatsink.
(I feel better switching both legs...No reason, really...I just do.)

I'm just exploring options.
Thanks, for the replies!

 

[Brumateur]

If I decide to use it, it will be with a Brewtroller & 12vdc power supply.
(Side note: Some PIDs actually do put out 12vdc to an SSR... Like this one that I own)

It's not about voltage level. According to relay spec
"Average coil consumption 1.7 W " It means you need 12 V source capable to provide 150 mA current. That PID you are referring can provide only 30mA. So relay will not be engaged if you connect it directly to PID.
I'm not very familiar with Brewtroller but I afraid you will have the same issue.

 

[BigFloppy]

beaten to the writeup

 

[Kit_B]

Aha...Yes.
Doing the math, it appears I need more than 141.666mA of power to operate the coil...I hadn't noticed that.
Also, the Brewtroller user manual seems to contradict itself.
In one area, it states 150mA output & in another, it states 100mA output.
I'm going to have to figure that out, if I want to even consider this one.

Thank you, very much!

 

[huntb]

Spend the $8 extra and get an SSR

 

[schematix]

Power to drive the relay aside, mechanical relays are not suited to tasks that involve frequent switching (more than once every few minutes), and especially with high currents. The contacts arc with each opening and degrade the metal until they eventually won't conduct. SSRs are cheap and if cooled properly last virtually forever. Easy choice.