Bilge Fans - independent or ganged

[weatherorknot]

Hi all,

I have a newly-acquired 2000 Carver 396/Diesel, and was only able to obtain the owner's manual for the 2002 model (from Carver), with a note that not much/if anything changed between 2000-2002. My question is about the Bilge Fans.

There are 4 separate bilge fans, each with their own circuit breaker. There is also a "bilge fan master" switch. Curiously, though, the 4 bilge fans are not wired independently, but rather ganged through fan #1 (i.e., fan #1 has to be on to allow any fan to be on). To be sure I'm explaining this well:
* With the Fan Master "on", and all 4 Bilge Circuit Breakers "off", no fans run. As expected.
* With the Fan Master "on", and only Fan #1 Breaker "on", then only number #1 fan runs. As expected.
* With the Fan Master "on", and only Fan #2 Breaker "on", **NO** fan runs. This is also the case for fan #3 "on" or #4 "on". This seems strange, because the fans would seem to be independent of one another. The wiring diagram in the owner's manual (different year), shows the fans as independent.
* With the Fan Master "on", and Fan #1 "on", and Fan #2 "on", then **BOTH** fans run. This is expected, but in contrast to the point above, it indicates the fans are ganged through Fan #1.
* Obviously with the Fan Master "off", no fan runs. With the Fan Master, what would be the value of ganging the fans through Fan #1???

The issue is that the Fan #1 circuit breaker has to carry the load of all 4 fans (because of the ganging), and it pops when all four fans are running. Any combination of 3 fans (e.g., #1, 2, 3, or #1, 2, 4, etc...always requiring #1 to be on), will run without problem.

Before I re-wire this back to having the fans independent, I wanted to check to see if there is any reason for the ganging, or if there folks that have similar ganged wiring.

Thanks
--Jim

[weatherorknot]

Hi all,

Just to let you know what I found out about this. The fans are not ganged, each having own independent power. However the power from Fan #1 activates a relay on all of the fans to allow the master fan switch to work. So, Fan #1 needs to be on to allow any fan to be on, but not all power is running through the Fan #1 circuit.

Happy boating!
--Jim

[g36]

although i had no idea with helping you with this problem i thank you very much for posting what you found out. i wish other people would do this. you see all these questions on different forums and just like on this one hardly anybody comes back and says what they found or even post the solution to the problem they had. i dont know about you but i've noticed not only here but other places people post and like never come back to read the advice provided (or they dont respond so you know they read it) its like they fell off the face of the earth. oh well i'll be quiet now , anyway thanks!

[Viper]

++1
Posting the solution serves to help everyone. It's unfortunate that folks take time out of their day to respond to an inquiry in an effor to help someone, only to be left hanging, never knowing if their's or others' suggestions did the trick, or if something entirely different worked that we could all learn from. So for that, I too thank you for keeping us in the loop! Now we all know.

[waybomb]

YES! Thanks!

[Hugo]

Mine are wired the same way. What you'll also notice is that when the ignition is on if the master blower #1 breaker is on the blowers will run (the ones that are on).

We have a switch on the helm to turn the blowers on/off and the only thing I figure that is for is to turn the blowers on after the ignition is off which you can also do from your DC control panel with a switch. When running the boat there's no control over the blowers with the helm switch.

I will probably remove the ignition feed that turns the blowers on so that the switch on the helm can be used to turn the blowers on/off...

My guess is it's wired this way for models that may have gas engines... Mine is a 444 which only comes in diesel but since it's an extension of the 396 the wiring is probably the same.

[CYO Admin]

This thread is sticky worthy. Thanks for the follow up!

[voyager57]

I have a 2002 57’ Voyager and a related question. There are the four breakers in the DC panel to supply power to each blower, but no switch on the helm or anywhere else to actually activate them. The only way I can activate them is when the starboard ignition is turned on. That is fine, but there are times that I’d like to run the blowers when the diesels aren’t running, such as when at anchor using the generator or after a run on a hot day to cool the engine compartment faster. The salon air conditioner has a fun time trying to catch up with the heat from the engine room constantly rising. I’m hoping by running the blowers for a bit after back at the dock will help cool things a bit faster.

Has anyone put in a separate manual on/off switch to accomplish this? I’m not an electrician and don’t want to start messing with the wires going to the ignition, but think it can’t be that complicated. I also have an upper and lower helm so am unsure if that complicates the issue. The starboard ignition from either station activates the blowers, so am unsure if they are wired in parallel or are separate going to the engine room. Any help is much appreciated!

[Hugo]

You sure you don't have a switch in the DC control panel next to the start for the generator? I have one...

Carver may be able to provide a schematic of how it's wired if you call them.

In a nutshell there are relays near the blowers. One side of the relay is going to be the load side with heavier gauge wires and that will go to the breakers. On the other side of the relay, the signal side is where your signal would come in to energize the relay from a switch for example. It can be figured out with a meter but will be easier if you get a schematic.

[Lyndon670]

As Hugo stated, regarding a DC panel.

On mine, the "other" DC panel (that Hugo speaks of) is on the aft bulkhead going into the engine room. The switches for all the blowers, windlass, bow thruster and charger on this panel.