Question about Hitachi EC12 Portable Electric 2hp Air Compressor, Oil Lubricated

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My compressor turns on and hums for 30 secs. and then the overload protection clicks. It will not start ''compressing'' Hitachi 2 horsepower 4 gallon

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Sounds like the pump is siezed or the starter capacitor has burnt out. I would try to get to the armature on the motor and see if you can turn it by hand.
If you can't turn it, remove the head of the pump to see if the valves are ok and that nothing is jamming the piston from moving ( rust, broken rings, bits of valve ).
If the piston is ok, it may be a siezed bearing.
Happy hunting

Posted on Apr 25, 2010


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When the compressor tries to come on, why does it click and hum, then clicks off?

Two causes for that situation. The compressor has a start relay and a overload mounted on the 3 prongs. When the relay/overload is bad, compressor will kick on, hum, then a click sound. The click is the overload. Or, the compressor is drawing too much power and the compressor is bad. 90% of time it's the relay/overload but you need to check and make sure fan is running by compressor and coils underneath are not clogged up. Poor air flow around compressor can cause overload to go bad.

Aug 19, 2015 | Refrigerators

1 Answer


did you change the ptc overload/ relay on the side of the compressor,the capacitor is in parallel with the start/run windings and the compressor will run without this part,but not with a bad ptc

Aug 30, 2012 | Frigidaire Refrigerators

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MCCF7W freezer stopped working

Your description of the problem seems to suggest that the compressor start relay may be bad. If there is a capacitor present it should be also tested. If start relay and/or capacitor is defective, you have the option to replace it with OEM; which may be a bit expansive, or use a Solid State Relay Overload Start Capacitor Combination. Before replacing or installing one of them, check the horsepower of your compressor. Solid state relay overload start capacitors are horsepower based.

Mar 31, 2012 | Refrigerators

2 Answers

Compressor runs and compress air,but when air setting is depleted compressor will not start to compress more air.If you waite it will start some times do think this might the compressor switch

If it doesn't try to start, then it could be the pressure switch. Another suspect could be the thermal overload on the motor. The motor (or just the overload) might be overheating and shutting the unit off, then allowing it to restart when it cools.

Is there any humming, or does it blow the breaker? When ot shuts off, do you hear a brief hiss of air?

If there is humming or breaker blowing on restart, or no hiss of air at shutoff, the pressure switch unloader valve is probably bad. If the air blows off, and there is no humming, and the compressor doesn't reliably start, it is probably the pressure switch. If pressure drops too low, give the pressure switch a tap with a screwdriver. If it starts then, the pressure switch is your problem.

Jun 02, 2011 | Air Tools & Compressors

1 Answer

My kenmore mod#2539183511 chest freezer comes on @30 sec goes off for @3-5 sec tries again.Need diag help or wiring diagram.

Sorry to read about your problem. you can have many different problems.

a wiring diagram will not help you in this case. all 3 items below at at the compressor.
odds are you will have to have the compressor replaced.

1. Failing compressor
2. Defective start cap
3. Defective overload protector

I suggest you call a service company.

I have tried to help you. Please help me, by Vote/Rate my response. Thanks.

If you live in the Denver area, I can help you.

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Jan 02, 2011 | Kenmore 12.8 cu. ft. / 362 liter Chest...

1 Answer

My EC12 will not start. No sound, when trying to turn fan in rear it feels completely froozen solid.

hi there, in that case totally busted,there are motor protection should be checked if this are open. 1.check the source of current on circuit breaker using multi tester.if there is source or voltage supply.if nothing voltage supply reset breaker. 2.if current is available on circuit breaker check the overload protection relay if there is reset over load protection.try to power on. 3.check the pressure switch if open,it always normally close meaning the contact-or is closed if busted,replace pressure switch. 4.if still not work pull out motor and check this to electric motor service center. 5.check also the mechanical parts by cracking flywheel pulley of the compressor.if no rotation on flywheel pulley have check on this.if no motion it affects the motor protection. fix my rate and have a nice day thanks a lot.

Apr 19, 2010 | Hitachi EC12 Portable Electric 2hp Air...

1 Answer

Fridge and freezer are warm, i can hear a fan running, and i think what sounds like the condenser turning on, theres a click followed by a hum for a few seconds then it shuts off. It repeats this every 30...

at the back of your refrigerator, you will see the motor compressor below, at the side body of the compressor you'll find a small box attached to the body where the wires come in, take out the cover, before doing that, unplug it first. then take the cover out. now plug it, don't touch it.

see if you can hear any click sound then it will shut off. if yes unplug it and take out the overload relay attached to the compressor where the wires are connected. try to replace it, just remeber the wire matching.

Nov 05, 2009 | Maytag PTB1954GR Top Freezer Refrigerator

1 Answer

I have a Whirlpool Side by Side Refrigerator Model # ED25PQXFW01. It makes a clicking noise about every 2 minutes almost sounds like the compressor isn't turning off and the food is defrosting in frig and...

Clicking sound is the protective overload mounted on the side of the compresser to shut the power to the compressor off, should it be unable to start.
After cooling down, it will repeat to try to allow the compressor to start.
Two possibilities.
1. The start components for the compressor are mounted on the side of the compressor and include the protective overload. The parts here are A.the start relay(two styles solid state or current type), B.on some but not all models a start/run capacitor, and C. The overload that you hear clicking. To test these components, you will need a knowledge of electical and ability to use a VOM meter. If you lack these qualifications take them to an appliance parts house and in most cases they will test them for you.
2. Compressor failed. To be totally safe, this test should be performed by a qualified tech.
Compressors carry a 5 year warrant from date of sale, and if the extended warranty is purchased. 10 years.
To allow yourself the most accurate responses in the future on any device you might need help, it is best you start by giving the age of the device. If you don't know, best guess will do.

Oct 25, 2009 | Refrigerators

2 Answers

Hitachi ec12 motor hums after drop in pressue

There should be a pressure switch adjustment under the cover of the switch remove the cover and reset.

Feb 03, 2009 | Hitachi EC12 Portable Electric 2hp Air...

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