804A power transfer issue

[DBLE]

Genset has 100 hrs on it. Was operating fine, making power. I shut down to adjust fan belt, and change oil. Now seems doesn’t transfer power, power is generated to line side of contactor, transfer panel mounted transfer switch seems fine. Any ideas ? Any problematic known issues?

 

[Evvy Fesler]

Genset has 100 hrs on it. Was operating fine, making power. I shut down to adjust fan belt, and change oil. Now seems doesn’t transfer power, power is generated to line side of contactor, transfer panel mounted transfer switch seems fine. Any ideas ? Any problematic known issues?

Welcome!

Genset has 100 hours on it since it was last overhauled. It's a subtlety, but important to understand, and that's if the hour meter hadn't been disconnected or non functional and replaced as a result.

Did you download the Technical Manuals (TM) yet? You can find them here on this site for free.

All the TM's you need to work on the MEP-804A

This should be all the TM's you need to work on the MEP-804A generator set.

www.steelsoldiers.com

Evvy-

 

[DBLE]

Mullaney,
Thank you I’ll take a look, if it gets too deep may be beyond my skill set. Any idea in my area that a qualified service person or company. So west NH.

 

[kloppk]

Are you handy with a hand held meter?

Are any Fault Lamps illuminated after starting it?

 

[DBLE]

Kloppk,
Yes Sir reasonably well with a meter. No fault lamps when restarted.

 

[Guyfang]

Gen set has 100 hrs on it. Was operating fine, making power. I shut down to adjust fan belt, and change oil. Now seems doesn’t transfer power, power is generated to line side of contactor, transfer panel mounted transfer switch seems fine. Any ideas ? Any problematic known issues?

So, its a matter of the K1, (AC output contactor) not closing? When you push the S5, (AC Contactor on/off switch) up, the DS7, (AC contactor on off light) comes on? Or not?

 

[DBLE]

Gen set has 100 hrs on it. Was operating fine, making power. I shut down to adjust fan belt, and change oil. Now seems doesn’t transfer power, power is generated to line side of contactor, transfer panel mounted transfer switch seems fine. Any ideas ? Any problematic known issues?

So, its a matter of the K1, (AC output contactor) not closing? When you push the S5, (AC Contactor on/off switch) up, the S7, (AC contactor on off light) comes on? Or not?

 

[Guyfang]

?

 

[DBLE]

Guyfang Sir,
S5 contactor switch up, on, S7 AC contactor light not on.

 

[Guyfang]

This kinda narrows it down a bit.

What makes you think the S5 is good? Did you test it? Its rarely a problem.

Try this. Place the S1, (Master switch) in the run position.
Place the S7, (Battle Short switch) in the up position. Push the S5 up, to the on position. Do you get a DS7, (AC interupter light) light come on? Do you hear a clunk?

 

[Guyfang]

Its 01:19 here, and I am getting ready to sign off. So if you can test it, do so.

 

[Guyfang]

If the DS7 will not come on and you do not hear a clunk, Turn everything off, and remove the K1 and take it apart. It may be bound up inside. Its not rocket Science.

 

[DBLE]

This kinda narrows it down a bit.

What makes you think the S5 is good? Did you test it? Its rarely a problem.

Try this. Place the S1, (Master switch) in the run position.
Place the S7, (Battle Short switch) in the up position. Push the S5 up, to the on position. Do you get a DS7, (AC interupter light) light come on? Do you hear a clunk?

 

[DBLE]

Guyfang Sir,
S1 in Run position , (unit not started S1 only in run position), S7 battle short SW up lamp is illuminated. S5 AC interrupter SW up, lamp is not lit, no clunk heard, (as it seems contactor does not pull in, assuming that’s the clunk you are referring to?)

 

[Evvy Fesler]

Guyfang Sir,
S1 in Run position , (unit not started S1 only in run position), S7 battle short SW up lamp is illuminated. S5 AC interrupter SW up, lamp is not lit, no clunk heard, (as it seems contactor does not pull in, assuming that’s the clunk you are referring to?)

Yes, that's what he means. The contactor is a heavy duty relay. A low voltage controls it via the switch S5. It clunks when it pulls in.

 

[DBLE]

Evvy,
Understood appreciate it, thank you for the clarification. Communication thus far is clear.

 

[Guyfang]

Something else you can do.

1. If the K1 is still in the set, Do the same test with the S1 and S7, and mesure with your multimeter at K1-X for 24VDC, while someone else pushes the S5 to the up position. Then do it again with K1.Y, as sometimes the wires get hooked back up wrong. A relay is not polarity sensitive, will work if Pos. and Neg are interchanged. Do you get voltage?


Or, if K1 is out, simply take two wires from the Batteries, and go to K1-X and K1Y. touch the terminals, and the K1 should work. If not, then take it apart. Should have wrote this last night, but ran out of time.

 

[DBLE]

Guyfang Sir,
Thank you. I’ll report back when procedure’s completed.

 

[Guyfang]

On 15 Feb. 1993, people stopped calling me sir. So should you. Guy works just fine.

 

[DBLE]

On 15 Feb. 1993, people stopped calling me sir. So should you. Guy works just fine.

Guy, Understood, in locating K1 (power transfer contactor, it is a bit Inaccessible, it appears the top of the genset will need to be removed for adequate accessibility.)Rain is forecasted here in the New Hampshire, this machine is not yet undercover. I’ll respond once troubleshooting procedure as you have detailed is executed. If the K1 coil is the failed culprit? (Yet to be determined) are they available As a direct replacement? Or source a contactor of proper coil and rated contact amperage ?
best Vic,