MEP-002A Not producing power

[Triple Jim]

CT1 readings are a little high at .7, .7, and .65.

Did you touch the meter leads together and read the ohms, then subtract that from the value you got for the transformer windings? Reading very low resistances like you're doing is a little tricky.

 

[mtfleming]

Exciter voltage. Main gen will not light off.

How do I read gen windings? As far as I know rotating diodes are ok.

 

[mtfleming]

Did you touch the meter leads together and read the ohms, then subtract that from the value you got for the transformer windings? Reading very low resistances like you're doing is a little tricky.

I will try that.

 

[Guyfang]

Open up TM 5-6115-584-34.
Turn to page 8-4, (Or PDF reader page #153)

h. Testing Generator Stator.
(1) High Potential Test. Test generator stator as
given in paragraph 8-2e of this manual. Replace
stator having faulty insulation.
(2) Winding Resistance Test. Perform winding resistance
test using a Kelvin bridge. Follow the manufacturer’s
instructions given on the bridge. Resistance
readings should be made on the pins of P9 and
P10 (see figure 8-3). Resistance between lead pairs
T 1- T4, T2- T5, T3- T6, T7- T1 0, T8- T11 and T9
- T12 should be 0.355 ± 0.036 ohms at 77°F (25°C). Refer
to the table in figure 8-3 for location of the terminals.
Also check resistance between each pin A through F
of P9 and P10 and the stator frame. Low resistance
indicates a shorted stator.

 

[Ray70]

Cause' everyone's got a Kelvin Bridge or 2 in their tool box....

 

[Guyfang]

The man asked how to check it. No one answered. And maybe he can find someone in town who has one. Oh Yee of Little Faith!

 

[Tinstar]

I had never heard of a Kelvin Bridge and had to look it up.

Learn something new here everyday.

 

[Chainbreaker]

I think I found one.! Not exactly sure how to use it... but I can see having one in my toolbox.

 

[Ray70]

I'd rather have yours than the on I found.... yours fits better in a toolbox too...

 

[mtfleming]

Open up TM 5-6115-584-34.
Turn to page 8-4, (Or PDF reader page #153)

h. Testing Generator Stator.
(1) High Potential Test. Test generator stator as
given in paragraph 8-2e of this manual. Replace
stator having faulty insulation.
(2) Winding Resistance Test. Perform winding resistance
test using a Kelvin bridge. Follow the manufacturer’s
instructions given on the bridge. Resistance
readings should be made on the pins of P9 and
P10 (see figure 8-3). Resistance between lead pairs
T 1- T4, T2- T5, T3- T6, T7- T1 0, T8- T11 and T9
- T12 should be 0.355 ± 0.036 ohms at 77°F (25°C). Refer
to the table in figure 8-3 for location of the terminals.
Also check resistance between each pin A through F
of P9 and P10 and the stator frame. Low resistance
indicates a shorted stator.

Thanks so much for the information!

 

[peapvp]

@mtfleming what test equipment do you have readily available?

 

[mtfleming]

@mtfleming what test equipment do you have readily available?

Only an ohm meter

 

[peapvp]

Only an ohm meter

Thank you, would it be possible for you to post a picture of this ohm meter which will give me a better idea to explore some testing options for you?

 

[mtfleming]

Thank you, would it be possible for you to post a picture of this ohm meter which will give me a better idea to explore some testing options for you?

I think somehow I uploaded it twice. Sorry it took so long for me to reply. All help is appreciated. I may be able to work on it some Monday.

 

[mtfleming]

Guyfang said something about l have exciter voltage but the generator would not light off. I have checked resistances on stator and think they are okay. To check for a short I just connect one lead to body of gen head and other lead to each pin of J9 and J10? Since the exciter produces a little power at the convenience outlet, do you think maybe the problem is in the rotor? I wonder what a gen head would cost?

 

[mtfleming]

Guyfang said something about l have exciter voltage but the generator would not light off. I have checked resistances on stator and think they are okay. To check for a short I just connect one lead to body of gen head and other lead to each pin of J9 and J10? Since the exciter produces a little power at the convenience outlet, do you think maybe the problem is in the rotor? I wonder what a gen head would cost?

Guyfang said something about l have exciter voltage but the generator would not light off. I have checked resistances on stator and think they are okay. To check for a short I just connect one lead to body of gen head and other lead to each pin of J9 and J10? Since the exciter produces a little power at the convenience outlet, do you think maybe the problem is in the rotor? I wonder what a gen head would cost?

I don't know which pins are A-F in the instructions on reading them to ground, but I numbered the pins according to a diagram in the TM. Here are the results:

#1 9.9 ohms
#2 7.0 ohms
#3 0.8 ohms
#4-6 open
#7 9.8 ohms
#8 7.0 ohms
#9 1.0 ohms
#10-12 open

Are these good?