CO Monitor replacement for generator shutdown option

Pilot

Active Member
May 7, 2009
294
Chesapeake Bay
Boat Info
2009 370 Searay DA
V Drives
Engines
Twin 8.1's
Does anyone know how to retrofit a newer Fireboy-Xintex to an older 6 wire set-up?
I have the old 6 wire CMD-4M-RLY-FCB unit. Its discontinued and the replacement version is only 2 wire. The older unit had a generator shutdown feature and an extra 4 wires. The result is now the generator won't work as the old CO monitor is EOL. I've been told by Searay that there may be a work around if I buy the unit, along with an optional cover (I assume that cover has the extra sensor and wires). Then, I have to manually wire it to the generator (Kohler 5EC).

I can't find anything on this procedure. photos, diagrams, video etc would be great.

Thanks!
 
That unit is older? I just bought one last year at West Marine? When did they discontinue it? (maybe mine is two wire - I guess I don't know)
 
Does anyone know how to retrofit a newer Fireboy-Xintex to an older 6 wire set-up?
I have the old 6 wire CMD-4M-RLY-FCB unit. Its discontinued and the replacement version is only 2 wire. The older unit had a generator shutdown feature and an extra 4 wires. The result is now the generator won't work as the old CO monitor is EOL. I've been told by Searay that there may be a work around if I buy the unit, along with an optional cover (I assume that cover has the extra sensor and wires). Then, I have to manually wire it to the generator (Kohler 5EC).

I can't find anything on this procedure. photos, diagrams, video etc would be great.

Thanks!

I think this Xintex document details what you need to do:

http://www.fireboy-xintex.com/wp-content/uploads/2017/03/Upgrading_CMD5-MD_CO-Alarms.pdf

With the new CMD5, you will need an additional relay module, the RCM-5, to maintain the same functionality of the CMD-4M-RLY which had the relay internal.

Alternatively, you can use a similar offering from MTI Industries (Saf-T-Alert brand) which has the relay internal to the unit:

https://www.mtiindustries.com/products.asp?cf=1&ti=0&ci=2&si=13&pi=91

Hope this helps...
 
I think this Xintex document details what you need to do:

http://www.fireboy-xintex.com/wp-content/uploads/2017/03/Upgrading_CMD5-MD_CO-Alarms.pdf

With the new CMD5, you will need an additional relay module, the RCM-5, to maintain the same functionality of the CMD-4M-RLY which had the relay internal.

Alternatively, you can use a similar offering from MTI Industries (Saf-T-Alert brand) which has the relay internal to the unit:

https://www.mtiindustries.com/products.asp?cf=1&ti=0&ci=2&si=13&pi=91

Hope this helps...
 
Thanks Stephen:

I thinks thats what I need. I hope the connectors all match up. Hard to find a lot out there own this.
Do you know if I just disconnect the old unit entirely, will it prevent the generator from working?
 
Yes, the absence of the detector should prevent the generator from running as it provides a NC (normally closed) relay contact.

Of course, it can be bypassed by shorting those two wires in the harness; however this is clearly not advised for safety reasons.
 
Yes, the absence of the detector should prevent the generator from running as it provides a NC (normally closed) relay contact.

Of course, it can be bypassed by shorting those two wires in the harness; however this is clearly not advised for safety reasons.

Thanks again Stehen. I appreciate the response and the help. I agree, I don't want to mess around especially when sleeping under gen power.
 
I'm getting ready to undertake this project as well.... Going from CMD-4 to CMD-5. However, I'm uncertain on where to mount the new RCM-5, as I'm guessing I've got to find the brown, yellow, and white wires that precede the first monitor. Any suggestions from those that might have already done this?
 
Just done this on a 330DA... we were able to get to the backside of the original as it was in a closet behind a removable panel. We simply ty-wraped the relay module to an existing wiring harness.
 
Thanks for the insight Jim! I posted this question on another group platform and received a similar response. I assumed that the original monitors had a separate relay, but later learned that the original monitors had built-in generator shutdown relays, whereas, the new monitors require the separate relay.

Seems that the approach is going to be to find the most accessible monitor, and tie the relay module into the backside wiring harness. I've got three monitors, so its not clear if I will have to find the first in the line, or if I can tie the relay anywhere in the line of monitors. I'm guessing the latter.

Since I haven't found much on this topic, I'll try to remember to post my results when complete.
 
I would agree... with three monitors I would think the relay contacts are all in series so that any one would shut down the generator.
 
DISCLAIMER: I'm not an expert, just wanted to post a update on how I did this in the event that it will help someone else out in the future...

I had the original Fireboy CMD4 Interconnect models, meaning that three CMD4 units were installed with built-in relays to shut off the generator when any unit was triggered. These are no longer made and any replacement requires the CMD5-MDI-R, which doesn't have built-in relays. If you have the generator shutdown feature, you must also install the RCM5 relay within the system.

The original CMD4s have the following wires: red (+), black (-), yellow (signal), brown (?), and two white (normal closed circuit, that when open, shuts down the generator). When disassembling the CMD4 wiring, I was surprised to find that the brown wire is not in use, so I ignored this wire.

The next step was to find a location for the RCM5 relay that is close to an existing monitor. It needs positive, negative, signal, and two ends of the white (normal closed) circuit. The best location that I found for this was behind the port side closet in the master stateroom. Removed the panel inside the closet on the forward facing side. It is in this location that I made sure that the two white wires where terminated in the relay at the Common (C) and Normal Closed (NC) post.

For the two remaining CMD5 units, I spliced the red, black and yellow wires to the existing harness. The two white wires for the remaining 2 units were butt spliced together, in order to keep the white wire circuits closed. These white wires are not wired into the two remaining CMD5 wiring harness. When any monitor is triggered, it sends a signal (thru the yellow wire) to the relay. The relay will then open the white wire circuit, thus killing the generator.

Finally, when complete, I tested the monitors, by running the generator, and then pressing and holding the "test" button on the monitors, to make sure that the generator will shutdown when triggered.

Hope this helps someone else on this project...
 
Need to do the same. I only have the one CO2 detector but need the relay to shut down the generator. Is there a kit that has the relay and the detector?
 
Not aware of any kit, but it's really only two devices to order: CMD5-MDI-R and RCM5 relay in my case. If you're not sure of which CMD5 to order, I found the folks at Fireboy, very helpful.
 
Not aware of any kit, but it's really only two devices to order: CMD5-MDI-R and RCM5 relay in my case. If you're not sure of which CMD5 to order, I found the folks at Fireboy, very helpful.
Thanks - just ordered mine. Sounds like they are backordered. I ordered mine in black - thinking it will blend in more.
 
Eddie,

When you cut the wires which relay poped? I did the same and now the two on the port side are not working. I was also wondering how do you determine if you can add the generator cutoff? I understand I would need the relay module
 
Depending upon the model of your generator, you may or may not have the generator cutoff. In my case, posted above, the white wires are the generator cutoff relay. If you don't have white wires in your wiring bundle, I would reason that your generator doesn't support the monitor cutoff. Probably best to look up your model number to confirm.
 

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