Block Heater

[opusd2]

When working on refrigeration units and HVAC systems, I sometimes am told to replace timer and relay components that are good yet so I hang on to them instead of tossing them. Combined with a T-Stat, you can make a really neat little thermostatically controlled or time controlled relays that allow higher amperage's to pass through them and then I can include my battery maintainer I install on board my trucks as well as other devices I may have installed for assistance or redundancy.

 

[f-two-fiddy]

The Block heater is closer to 1500 watts than most peeps think. You need a decent 12 ga extension cord and a 15 amp (minimum) circuit to safely power it.

 

[leftcoastjeff]

Thanks f-two-fiddy, I measured with a VOM, I was concerned it wasn't working right, it sounded like a coffee pot starting up!

Maybe some heaters are different, I've only tested one.

Needless to say, it draws a lot of power, like that little electric heater that trips the breaker once-in-a-while.

Add any cheap extension cord, I think your looking for trouble, IMHO

If it's going to lessen the start-up damage and smoke, I'm all for it.

LCjeff

 

[snicklas]

When you first plug the block heater it, you can hear a "sizzling" of a boiling sound, much like a coffee pot. That is how I tell if mine made contact when I plug it in.

On another note, to figure out how much current these pull, to make sure you are supplying them with sufficent cords, breakers and timers, it is fairly simple to figure out.

Power is "easy as pie" to figure out power comsumption (watts) the formula is:
P=I x E - Power (in Watts) = I (Current) x E (Voltage)

In this case we know power and voltage. So to figure out how much currect draw that is:

I = P/E Current = Power (in Watts) divided by Voltage

I = 1500/110

I=13.64 Amps.

That 13.64 Amps is at the initial startup current draw. As the block heater warms up it will draw less current (Just like glow plugs).

So I would use at least a 15 Amp HIGH QUALITY timer, a $5 timer from wally world or Big Lots may not be sufficent enought.

I know this discussion comes up alot this time of year, so I thought I would show everyone how to get the answer to the question...

Math lesson over.....

 

[opusd2]

That reminds me of taking my test to get NATE certified for HVAC! All that math you never think you need to use until the one day you actually use a little, then you are glad you keep a little cheat sheet with you.

 

[snicklas]

That reminds me of taking my test to get NATE certified for HVAC! All that math you never think you need to use until the one day you actually use a little, then you are glad you keep a little cheat sheet with you.

See Mom and Dad...... All that money for college wasn't wasted........

Not really, I would not have the job I do today if I had not gone to ITT and got my BASEET.......

 

[opusd2]

No kidding!

 

[HammerDown]

Put her on a timer....so it turns on 2 hours before you start her....and shuts off just before you start her in the morning. You can get them pretty cheap and they save you a lot of power in the long run by only heating up when you need it to.

Yep...that's how I do it, only on REALLY frigid mornings.

It's not too much fun changing out a bad block heater >as some coolant always runs down your sleeve etc.