Ingersoll Rand problems

[Daz2012]

Hi all,I'm new here so be gentle with me

I have a compressor that runs an IR type 30 2 stage pump (not the original pump to the compressor but one I bought 2nd hand to replace a knackered Fiac pump)
It worked fine for about 7 or 8 years then over the last 18 months it's been struggling to keep up with the demands on it.....the thermal overload would cut in a couple of times a day and have to be reset....but apart from that it was still useable.
Anyway I decide to give the head an overhaul,new valves,valve plate on the high pressure side and new gaskets.
I also replaced the crankcase front gasket and noticed the plunger for the unload valve was missing its o-ring,so duly fitted a new one.

This is where my problems begin.
The thermal overload is cutting in virtually every time the tank fills up and sometimes even before the tank is full.
I adjusted the unload valve as with the new o-ring it wasn't working (I assume having no o-ring in before was allowing air to seep past and relieve the pressure in the cylinders) but it is working now.

The only other maintenance I carried out was the drive belts were a tad loose so I adjusted them up.

Any suggestions would be most helpful.
Cheers Daz

 

[tigler]

What power is the drive motor and what model of T30 is the pump ? ?

 

[MonsterLandrover]

Thermal overload on the motor? Could be an issue with the motor rather than the pump.

 

[Daz2012]

What power is the drive motor and what model of T30 is the pump ? ?

It's a 242...as for the power I think it's single phase but I'm not 100%,I'd have to check tomorrow

 

[tigler]

It's the kilowatt rating I'm after, for a 242 it need's to be 2.2 at least, preferably 3kw.

 

[Daz2012]

I'll get the specs tomorrow....although it's the same motor I've been using for 9 years

 

[tigler]

If the KW rating is adequate, the tripping could be a sign of a capacitor failing.

 

[Daz2012]

I know when I built the thing in 2003 I changed the pulley on the motor using some formula or other because obviously the IR pump needs to rotate slower than the old aluminium pump than was there

 

[graffian]

I'll get the specs tomorrow....although it's the same motor I've been using for 9 years

Plate on the back of the pump usually has the bore and stroke on
it, that's probably enough info for people to tell you how fast the pump should be run and what size motor it should have on it.

 

[tigler]

See posts above

 

[eil]

While you are at it give the non return valve on the tank a look over and clean, also check the contacts on the contactor for overheating, As above it does sound like a capacitor could be going down.
The motor pulley on a 3hp, 1450rpm would be 7", giving you around 650 rpm when up to pressure.

 

[Daz2012]

Would you believe it,it's been working all afternoon without problem.
Still had the same issues this morning so I spoke to the fella who supplied the parts for the pump and he suggested making sure I had full supply voltage and then probably look at changing the overload switch as they can be prone to faults.
So I put a meter across the power switch,237 volts,and that's all I've done yet afterwards it has been running faultlessly.

I'm think a bad electrical connection somewhere ?
The compressor does vibrate quite a lot compared to others I've seen so maybe that's causing an intermittent wiring fault ?
Hopefully I've got a guy coming tomorrow to check it over.

I did get some details tho
The motor is a Brook Hansen ped905,2.2kw,2800 rpm with a 4" pulley.
The pump is a type 30 4" x 2 1/2" x 2 3/4" with a 15" pulley

 

[tigler]

I wonder if the supply voltage in your area was low at the time the problem occurred ?
One thing though, I got my numbers mixed up on the pump, the 242 should have a 5hp drive motor.
Vibration, it shouldn't !! Check for runout at the the edge of the flywheel. Bent cranks on pumps with big flywheels is a common problem due to being dropped when handled.

 

[the snooper]

there was also a thread on here some time ago where the op had adjusted his drive belts and had over done it, it was also causing problems

 

[Daz2012]

there was also a thread on here some time ago where the op had adjusted his drive belts and had over done it, it was also causing problems

That's something I checked today,I put them back to what they were before,the slightest difference to be honest and it didn't make any difference

 

[Daz2012]

I wonder if the supply voltage in your area was low at the time the problem occurred ?
One thing though, I got my numbers mixed up on the pump, the 242 should have a 5hp drive motor.
Vibration, it shouldn't !! Check for runout at the the edge of the flywheel. Bent cranks on pumps with big flywheels is a common problem due to being dropped when handled.

Yeh I know the pump is oversize for the compressor,heck I had to widen the mounting platform with some angle iron just to have somewhere to bolt to but beggars couldn't be choosers,I picked it up for 60 quid and I was desperate to get my compressor working as I use it everday

 

[tigler]

Understand but it will make the motor work hard. Would be a good idea to check the current draw on load.

 

[eil]

You could have the 242 with motors generally ranging from 3hp up to around 7.5hp it all depends on how much cfm and pressure thats needed.
What pressure do you run yours up to ?.

 

[Daz2012]

You could have the 242 with motors generally ranging from 3hp up to around 7.5hp it all depends on how much cfm and pressure thats needed.
What pressure do you run yours up to ?.

At the tank ? no more than 140

 

[eil]

At the tank ? no more than 140

Similar to mine then, but your rpm is a tad high compared to mine, but as you say its lasted quite a few years, its done well for a two pole motor considering.
Like I said the pump on mine runs at about 650rpm, I have it cutting out just before it reaches its max amp draw.