GE 6B Steam Injection Control Valve Controls

C

Thread Starter

cacctuschris

Frame 6B,
MK4 Controls.
ADAC 90RC 250QT
-(Quarter Turn) Electric Valve Actuator (275 ft-lbs)
-Single-phase Motor (cap, limit switches, torque switches)
90CJ-1A
-receives 120VAC from dist pnl,
-sends to 90CJ-1B,
-has off switch
90CJ-1B
-valve controller/brake board,
-120VAC from 90CJ-1A,
-Sends ~10V AND COM to <RELAY 2>
-Takes Run and Dir signals from <RELAY 2> (L60WQRUN, L60WQDIR)

We've had troubles with these boards and our inventory is depleted. Documentation is not much in the manuals for the electrical operation, but it seems pretty straight forward. The MK4 side seems to be working well.

RUN & DIR => CLOSE signal
RUN => OPEN signal

Based on that;

-when both relays are open, there should be 0V from M1 to M3 and 0V from M2 to M3 on the brake board.

-when the RUN relay closes, there should be 120V from M2 to M3 and 0V from M1 to M3 on the brake board.

-when the RUN and DIR relay closes, there should be
0V from M2 to M3 and 120V from M1 to M3 on the brake board.

Currently, on both a "repaired" and a "last in stock" brake board, I have 120V from M2 to M3 and 120V from M1 to M3.
This is true for any input combination. Inputs do make the red light blink on the board.

The results are the same with the motor disconnected.

Motor resistance is a few ohms both M1,M2 to M3 in mid position (no limits made).

I have talked to valve vendors for a replacement setup (valve and/or actuator) but none of the newer options seem to handle the RUN & DIR scheme. I could use relays to turn run and direction into OPEN and CLOSE. But I'm hoping I'm not overlooking something simple.

Do you have experience with this setup and/or any advice that may help?

Have you successfully replaced one of these actuators or actuator/valves with something newer and interfaced it with the RUN and DIR relays?
 
cacctuschris,

>Have you successfully replaced one of these actuators or
>actuator/valves with something newer and interfaced it with
>the RUN and DIR relays?

I don't have access to any Mark IV elementaries at this writing, but I hope I can offer some assistance.

The reason there are L60WQDIR and L60WQRUN relays is that the ADAC actuator required multiple sets of contacts to operate correctly. Without access to a set of Mark IV elementaries I can't recall precisely what the two relays do, and when they are energized and de-energized. If I recall correctly (and it's been a long, Long, LONG time since I've given this any thought!) when one of the relays is energized the actuator is told to close, and when both of the relays is energized the actuator is told to open. I think (and this is a SWAG without Mark IV elementaries) the L60WQRUN relay is energized to tell the actuator to close the valve, and both L60WQRUN and L60WQDIR relays are energized to tell the actuator to open the valve--but I may be wrong about that.

In any case, that's what the ADAC actuator required to work properly; GE tried to use a single relay to do both--but it wouldn't work (because two sets of independent contacts were required).

If you can't or don't want to have someone make modifications to the Mark IV sequencing, I <i>think</i> you could use some interposing relays and wiring to "condense" the two outputs to one--which would tell a new actuator to either open or close. It all depends on what the new actuator requires. And, again, the reason there are DIR and RUN relays is that's because that's what the ADAC actuator required.

But, the "simplest" thing to do would be to modify the Mark IV sequencing to drive one relay, or two relays, and have one relay use both the NO and NC contacts of one of the Mark IV relay outputs energize for one direction, and de-energize for the other direction. Or have one of two relays energize for one direction, and the other relay energize for the other direction. That wouldn't be too difficult in Mark IV sequencing--it's just finding someone who can do that these days (with the hardware and skills).

I haven't given it much thought, but it seems it should be possible to use some wiring and interposing relays to convert the DIR and RUN outputs to a single relay, or two relays, to make a new actuator open and close. I haven't drawn it out, but in thinking about it it seems possible and relatively easy. It's just finding a power source for the interposing relays (spare 120 VAC or 125 VDC fuses in the <PDM>), and understanding what the new actuator might need.

I would start there--if you don't already know--by finding out what the new actuator requires (or what two or more different actuators require). One configuration might be one contact that closes to open the valve, and one contact that closes to close the valve (when both are open, the valve is to stay stationary--not move); I'm sure there are many for this type of valve actuator. And, then we can try to come up with a scheme that would work. If you have a vendor you've used before that can make Mark IV sequencing changes and would use them again, that might matters a little easier. If you don't, that might make matters a little more difficult, or if you don't know anyone who can make Mark IV sequencing changes.

Hope this helps!!!
 
C

cacctuschris

>If I recall correctly (and it's been a long, Long, LONG time
>since I've given this any thought!) when one of the relays
>is energized the actuator is told to close, and when both of
>the relays is energized the actuator is told to open. I
>think (and this is a SWAG without Mark IV elementaries) the
>L60WQRUN relay is energized to tell the actuator to close
>the valve, and both L60WQRUN and L60WQDIR relays are
>energized to tell the actuator to open the valve--but I may
>be wrong about that.

You had a 50/50 shot ;)

I'm impressed as always, I have them in front of me otherwise I wouldn't get it right. I've been getting it wrong all day in fact.
but:
L60WQL OR L60WQR => L60WQRUN
L60WQL AND NOT L60WQR => L60WQDIR

>In any case, that's what the ADAC actuator required to work
>properly; GE tried to use a single relay to do both--but it
>wouldn't work (because two sets of independent contacts were
>required).

Thanks for the background, your recollection of why they had to do RUN and DIR makes sense. I definitely couldn't find another actuator that accepts inputs like that.

>If you can't or don't want to have someone make
>modifications to the Mark IV sequencing, I <i>think</i> you
>could use some interposing relays and wiring to "condense"
>the two outputs to one--which would tell a new actuator to
>either open or close. It all depends on what the new
>actuator requires. And, again, the reason there are DIR and
>RUN relays is that's because that's what the ADAC actuator
>required.
>
>But, the "simplest" thing to do would be to modify the Mark
>IV sequencing to drive one relay, or two relays, and have
>one relay use both the NO and NC contacts of one of the Mark
>IV relay outputs energize for one direction and de-energize
>for the other direction. Or have one of two relays energize
>for one direction, and the other relay energizes for the
>other direction. That wouldn't be too difficult in Mark IV
>sequencing--it's just finding someone who can do that these
>days (with the hardware and skills).
>

So sequence editing L60WQL off of the top rung
and sequence editing NOT L60WQR off of the bottom rung...

Would turn the L60WQRUN relay into a raise (OPEN) relay
and L60WQDIR into a lower (CLOSE) relay.

In fact, I could possibly just edit the top rung.

I've done it once before, and I couldn't get comms right at first. I think the book was wrong, but with the help of a head-honcho guru who just happened to be visiting for other reasons, we found that parity needed to be 1.5 and got the job done. It had been a very long time for him too, this was several years ago.

I made the cable (from the manual's directions) and it works with a USB adapter and DOSBox. From there terminaling in and making the changes was pretty cookbook and 'simple' like you say.

>I haven't given it much thought, but it seems it should be
>possible to use some wiring and interposing relays to
>convert the DIR and RUN outputs to a single relay, or two
>relays, to make a new actuator open and close. I haven't
>drawn it out, but in thinking about it it seems possible and
>relatively easy. It's just finding a power source for the
>interposing relays (spare 120 VAC or 125 VDC fuses in the
><PDM>), and understanding what the new actuator might need.

I worked something out with 2 extra relays also, but I didn't really like that the lower signal would have to pick up a relay to block the close signal. It's probably doable though.

2 more relays to handle the 120AC motor current, and all set.

>I would start there--if you don't already know--by finding
>out what the new actuator requires (or what two or more
>different actuators require). One configuration might be one
>contact that closes to open the valve, and one contact that
>closes to close the valve (when both are open, the valve is
>to stay stationary--not move); I'm sure there are many for
>this type of valve actuator. And, then we can try to come up
>with a scheme that would work. If you have a vendor you've
>used before that can make Mark IV sequencing changes and
>would use them again, that might matters a little easier. If
>you don't, that might make matters a little more difficult,
>or if you don't know anyone who can make Mark IV sequencing
>changes.

It's basically 3 wire 120V reversing motor HOT FWD, HOT REV, NEUTRAL, AND THE 120V AC is already there for the brake board. Going with a Rotork IQ actuator.

>Hope this helps!!!

It was a big help, I was headed this way, but gave me the confidence boost I was looking for. Thanks!
 
cacctuschris,

Glad to have been of some help!

I was thinking the same thing when I was writing my previous response: I have a 50/50 chance of being right, and that's better than most casino games.

Please write back to let us know how you fare!
 
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