MEP-831 no output

[Johnf]

New owner and first post. I’ve been following table 4-4 unit level trouble shooting and need help. I have voltage at A8 and A1/B1 on K1. No voltage at A2/B2 and 26v dc at terminal 2 on K1. I checked S5 and it checks fine. I don’t hear a click at K1 when I switch to closed on S5. I replaced K1 but still the same so I obviously missed something. Next steps?
John

 

[kloppk]

John,

With the S1 in RUN depress the lens of the contactor lamp and verify it illuminates.
Are any Fault Lamp ON when the set is running? In none are illuminated then depress the Test/Reset button on the fault panel and verify all the lamps illuminate.
If all the above check out then...
Here are some pointers on how to figure out why the contactor isn't closing.
With the set running lift S5 and hold it up. Does the Contactor lamp illuminate?
If not then you'll need to verify the DC voltage at the following points when S5 is lifted.
All the following points should have ~ volts DC on them while S5 is UP.
Check them in this order
K12-12
K12-4
K15-12
K15-8
S7-8
S5-5
S5-6
S5-4
S5-1
S5-3
S5-2

Post up your results when you get a chance.

This path..

 

[Johnf]

John,

With the S1 in RUN depress the lens of the contactor lamp and verify it illuminates.
Are any Fault Lamp ON when the set is running? In none are illuminated then depress the Test/Reset button on the fault panel and verify all the lamps illuminate.
If all the above check out then...
Here are some pointers on how to figure out why the contactor isn't closing.
With the set running lift S5 and hold it up. Does the Contactor lamp illuminate?
If not then you'll need to verify the DC voltage at the following points when S5 is lifted.
All the following points should have ~ volts DC on them while S5 is UP.
Check them in this order
K12-12
K12-4
K15-12
K15-8
S7-8
S5-5
S5-6
S5-4
S5-1
S5-3
S5-2

Post up your results when you get a chance.

This path..
View attachment 859119

 

[Johnf]

Thank you! Since I posted this I found K15 isn’t working. I jumped the terminals with 24 volts and it’s not working. I’ve ordered the relay and will post the results once I get the replacement part. The relay has this nice little burn spot on the inside.

 

[kloppk]

FYI there are two different relays used in there. The 2 left relays K12 & K14 are 24 DC coils. The rightmost relay K15 has a 120 VAC coil.

Some people accidentally plug a 24 volt one in the K15 position. Not good for the relay coil and the poor LED inside the relay! Poof!

 

[Guyfang]

Greetings John,

In case you need to look at the TM's, they are located in the Forum TM section. Download only cost a few key strokes.
Please write your city in the location block. Thanks.

Oh, only 10-20 million people have thought the relays were all the same. Been there, done that.

 

[Johnf]

Greetings John,

In case you need to look at the TM's, they are located in the Forum TM section. Download only cost a few key strokes.
Please write your city in the location block. Thanks.

Oh, only 10-20 million people have thought the relays were all the same. Been there, done that.

Thanks. That one is 24vdc and is what was in it when I got it. That would explain the nice burn spot. I’ll order the correct one and give it a try. I have the TM’s and have been reading what others found to make my way this far.
john

 

[Johnf]

I replaced K15 with a 120vac relay and I have output. Thanks.

 

[DieselAddict]

Got to love a simple fix!