Oil Safeties, New vs. Old?

[Krohnie]

I am working with some large commercial equipment to which I have inherited all the problems for the past twenty or so yrs.

Oil safeties, I am working with basically two different types.

1. The "Older" style that has one line on the suction side of the compressor and the other tees off of the oil pump(Backside of Comp.)

2. Brand New safety that screws right into the base of the oil pump.

Should I consider replacing the oil safeties that have been on the units for the last ten-twenty yrs with the new Sentronic ones; or leave them
be?

[jpsmith1cm]

I am working with some large commercial equipment to which I have inherited all the problems for the past twenty or so yrs.

Oil safeties, I am working with basically two different types.

1. The "Older" style that has one line on the suction side of the compressor and the other tees off of the oil pump(Backside of Comp.)

2. Brand New safety that screws right into the base of the oil pump.

Should I consider replacing the oil safeties that have been on the units for the last ten-twenty yrs with the new Sentronic ones; or leave them
be?

A few things to consider.

All oil controls should be tested monthly. Don't just push the button either, that proves squat.

Depending on age, you may not be able to use sentronics without replacing oil pump.

Are the old controls adjustable? If so, were they zeroed out by a hack? Those I would replace, ASAP.

I have had more trouble with sentronics, especially the new sentronic+ than mechanical controls. From a protection standpoint, I don't think that one is superior to the other.

[Krohnie]

Either of the controls are non-adjustable.

What kind of tests could you run on the controls?

What kind of trouble have you had with the Sentronoc+s? (I ask because I have been using these to replace failed/junk ones)

[davidd_danfoss]

My comment would be that the mechanical ones normally work great, but some of them tend to overheat causing nuasance trips. Sentronics ones have had problems with cracked board parts, and need to be cleaned on dirty systems.

[jpsmith1cm]

My comment would be that the mechanical ones normally work great, but some of them tend to overheat causing nuasance trips. Sentronics ones have had problems with cracked board parts, and need to be cleaned on dirty systems.

Yup, that's it, cracked boards, parts falling off of the circuit board, broken switches.


On the plusses, watch the LED. If I suspect that a control is bad, I just watch that for a few minutes. If it flickers or dims, junk the control.

Have had to clean a few sending units, but not as many since we started doing annual oil changes on those bad racks, that problem went away.

For testing purposes, on a sentronic, unplug the sending unit. The control should trip after 2 minutes. Be sure to verify that the control has voltage.

For the mechanicals, testing gets a little different. You need to energize the control circuit without energizing the compressor. This creates a 0 oil pressure condition to induce a failure.

Again, verify that there is voltage to the oil control because the contol cannot trip without it.

I emphasize that because we had an incident where a tech condemned 12 sentronics that wouldn't trip due to bad current sensing relays not energizing the controls.

I caught it too late and the price difference was substantial. Oopsie!!

[Krohnie]

My comment would be that the mechanical ones normally work great, but some of them tend to overheat causing nuasance trips. Sentronics ones have had problems with cracked board parts, and need to be cleaned on dirty systems

Most of the time my units are exposed to the elements and I get more water damage problems, but I recently had one that was installed and three days later the reset switch melted taking out the board behind it.

[jpsmith1cm]

Most of the time my units are exposed to the elements and I get more water damage problems, but I recently had one that was installed and three days later the reset switch melted taking out the board behind it.

Have to say that's a new one on me.

I think what davidd was referring to is that mechanical oil controls have a heater element in them for the time delay feature. If they overheat, they will trip.

[davidd_danfoss]

Have to say that's a new one on me.

I think what davidd was referring to is that mechanical oil controls have a heater element in them for the time delay feature. If they overheat, they will trip.

Your right on the heater part. Many times I have seen, especially in hot machine rooms w many start stops that the delay is shortened because the switch is hot to begin with.

[jpsmith1cm]

BAhhh. Just leave the cover off. :D

And if that heater thingy gets to hot, clip one of the wires going to it. That cools it down. No more nuisance trips... :eek:

[davidd_danfoss]

jp,
I hope people are smart enough to know what that little clip would do to the compressor...

[jpsmith1cm]

Do I need to post a disclaimer??

All post by this poster regarding clipping wires to heater thingies should be disregarded as this will render the control inoperative, void your warranty, scramble the internal parts of the compressor and cause all of your hair to fall out.

Sorry, I've just been a little goofy lately. My reaction to life's stress.

On a serious note, I have actually seen controls where the lead to the heater was clipped.

[-frozen-ocean-]

ifs theres nothing wrong with them i'd them them.could get 20 more years out of them:D and if you were to replace one why not replace it with the same type of mechanical ofs.

[Dowadudda]

what's wrong with pushing the button? I like pushing the button. :D:D:D

I like the JCI and Sentronics. Good stuff mainard.

Testing oil switches monthly is new on me.

[jpsmith1cm]

Customers demands monthly oil safety switch testing under PM contract.

You would be AMAZED at the number of failed oil controls we had sitting, waiting to destroy a compressor.

Probably 40-50 in 35 stores. Fair mix of mechanicals and sentonics.

Monthly testing may not be entirely necessary, but regular testing should be part of a PM program.

[crackertech]

Customers demands monthly oil safety switch testing under PM contract.

You would be AMAZED at the number of failed oil controls we had sitting, waiting to destroy a compressor.

Probably 40-50 in 35 stores. Fair mix of mechanicals and sentonics.

Monthly testing may not be entirely necessary, but regular testing should be part of a PM program.

Our contract say's to test at least every three months.But my crew test
every month.Better safe than sorry.

[jwc64]

Our contract say's to test at least every three months.But my crew test
every month.Better safe than sorry.

When that contract requires you to buy that compressor, monthly it is.

[jpsmith1cm]

When that contract requires you to buy that compressor, monthly it is.

Exactly.

[davidd_danfoss]

Do I need to post a disclaimer??

All post by this poster regarding clipping wires to heater thingies should be disregarded as this will render the control inoperative, void your warranty, scramble the internal parts of the compressor and cause all of your hair to fall out.

Sorry, I've just been a little goofy lately. My reaction to life's stress.

On a serious note, I have actually seen controls where the lead to the heater was clipped.

No disclaimer needed. I was just saying that there are guys who do that... as you have seen too. But crap like that is always going to happen, at least until they pay to have it done right, by the people who can do it right.