need help with 003A

[justacitizen]

i have an MEP 003A that runs strong and carry a resistive load fine but it won't start the ac condenser unit. the main breaker trips instantaneously. i installed a soft start on the unit but it made no difference. i read the whole thread about the main breakers and have done a little work to see what i have. i checked the ac output box windings in the cvt to make sure the box isn't for an 002A and since the box has four wraps it seems correct to be for an 003A. the percent of load meter seems to run higher than the load though. i read that the main breaker for an 003A is the same as for the 002A and then i read it isn't the same????? also there is an adjustment inside of the ac output box? is this to adjust the trip on the breaker? the machine runs the house,hot water tank oven dryer well pump just fine but it will not start the ac compressor no matter what even by itself. does anyone have any ideas??? Thanks the ac condenser runs at about 24 amps on main power i will get the starting amps and return.

 

[Scoobyshep]

I never tried the 003 on my home, but in my shop it doesn't like my air compressor. There are typically 2 things that set off a breaker, thermal and magnetic. Thermal is for the long overloads and magnetic is for the sudden shorts. Problem there is motors can draw up to 10x their current on startup and tend to set off the mag trips.


What kind of soft start did you use?

Sent from my SM-S908U using Tapatalk

 

[justacitizen]

the momentary start amps measured 89 amps. the run amps are 25. this is measured on main power. measured with a fluke at the unit location

 

[Ray70]

My understanding is that an 003 main breaker is a 100A magnetic breaker and the 002 is a 50A.
My 003 doesn't like my 7.5hp air compressor, but it will start my 5 hp compressor.
The magnetic breakers typically hate motor starts, but I am a bit surprised the soft start on your AC didn't help.
I'm a little curious if you may have the wrong breaker in your AC reconnect box.
I've heard of people bypassing the magnetic breaker and utilizing a normal thermal breaker instead, but I've never tried it.

 

[justacitizen]

Thank You Ray70

I haven't yet positively identified the main breaker as correct to the 003A. i have read conflicting opinions that the main breaker on the 003A and 002A are the same but have a different trip setting???? how do i confirm the breaker? is the adjustable pot in the AC box where the adjustment for the breaker? the percent of load meter seems to read a little high also but i haven't confirmed this.

 

[Guyfang]

Instead of guessing, look.

First, whats the serial number of the set? See special info below, for the MEP-003A.

4. Special Information

a. (ALL) Identification of the usable on codes are:
Code Used On Serial Numbers

UOC A MEP-003A EZ00001 thru EZ00118
UOC B MEP-112A EZ00001 and UP
UOC C MEP-003A BZ00001 and UP
SERIAL NO RZ80001 THRU RZ80400

UOC A & C = MEP-003A
5925-01-050-0484
CIRCUIT BREAKER
72-5173
CD3-Z142-1



No UOC on the MEP-002A

MEP-002A
5925-01-050-0484
CIRCUIT BREAKER
72-5173
CD3Z142-1


There is also an old NSN, 5925-01-214-5416
Other part numbers:
299-3-4798-1
320-0462

 

[justacitizen]

Hello GuyFang
I envy your expert use of the manuals and how to read them. i get lost in the fog sometimes. also Thank You Very Much for posting that information.... it will prove very useful. I will get the serial numbers and return