Water heater button turns off shore power?

[Ed Childress]

I have a 1985 30' Catalina and when I have shore power on (both indicator lights on) and press the water heater button (switch or breaker button?) the shore power turns off. When I press the water heater button again and it releases, the shore power comes back on. I disconnected the heater element in the water heater and the shore power stayed on upon pressing the water heater button, so I replaced the heater element. No change. There is a temp regulator and emergency shut off switch on the water heater, but I'm now wondering if the water heater button is malfunctioning. I do not have an AC circuit diagram and would appreciate it if someone can send me one. Plus any suggestions as to what's causing the problem.

 

[Don S/V ILLusion]

Need more input to offer any advice -

What shuts off when you do that? The shore power breaker? The breaker on shore?

 

[jssailem]

The symptoms suggest the water heater is drawing a lot of current. Enough to overwhelm the breaker for the shore power. Are you using any other systems besides the water heater when this happens?

1. It could be that the Shore Power breaker needs to be replaced.
2. On the other hand, it could also be that when you add the water heater's amp demand to the other amp loads you are using, you exceed the 30 amp breaker. In this last case, the breaker is performing its intended function.

 

[colemj]

Do shore power breakers usually automatically reset? I've never had one that did.

I suspect it might be an automatic transfer switch that is disconnecting and reconnecting.

Mark

 

[Ed Childress]

I would love to see a circuit diagram for the AC circuit on my Catalina so I can see whether it is an auomatic transfer switch or shore power breaker and whether the water heater button is just a switch or some kind of breaker. I thought John's idea of water heater drawing too much current was the problem and assumed it was the element shorting out. When I removed it the was a lot of rust around the base of the element, but a new one didn't correct the problem.

 

[Ed Childress]

Don asked "what suts off" and I tried to reply, but this is my first post so I'm not sure I replied correctly. It is the indicator lights that tell whether the shore power is hooked up. The lights go out when I press the water heater button. I assumed that meant the AC power was being shut off, but I haven't checked to see. If not, why are the lights going out? I'll check that tomorrow.

 

[Don S/V ILLusion]

Don asked "what suts off" and I tried to reply, but this is my first post so I'm not sure I replied correctly. It is the indicator lights that tell whether the shore power is hooked up. The lights go out when I press the water heater button. I assumed that meant the AC power was being shut off, but I haven't checked to see. If not, why are the lights going out? I'll check that tomorrow.

What lights? Sorry to persist only with questions but I can’t figure out your answer without this info.

Assuming the ambient light in the boat go “out”, they are presumably run off DC (battery power). If I assume correctly you mean indicator lights, check the AC power (carefully) with a voltmeter. It might just be enough draw to lower the voltage sufficiently to create the appearance of power loss when it is only low voltage caused by a high resistance connection somewhere in the power supply side including the breaker panel. Anything loose or corroded? . That could also energize some breakers without tripping them.

if you mean to imply the boat ambient light go off, I have no clue how that could happen unless there is a battery Charge problem.

 

[JoeWhite]

Disconnect battery charger then turn on the water heater. The charger plus water heater may be too much draw. This may indicate it is time for new batteries or one of the batteries has gone bad.

 

[Ed Childress]

I think you may have something there, Don and Joe. I have suspected one of my two house batteries is going out. I'll be checking that tomorrow. There is a black component where the shore power connects to a post on one side and the power line leading from there to the boat AC circuit connects to a post on the other side. This small component (small plastic box with two posts) is attached to the instrument panel that folds down when you unlock it. I did check both posts for voltage and both are hot when the water heater is turned off and only the post where the shore power is coming in is hot when the button for the water heater is pushed in. That component appears to be a breaker that resets itself when the excessive current is corrected. Never heard of such, but may be. Looks like our boats have the same name, Joe.

 

[Davidasailor26]

There is a black component where the shore power connects to a post on one side and the power line leading from there to the boat AC circuit connects to a post on the other side. This small component (small plastic box with two posts) is attached to the instrument panel that folds down when you unlock it. I did check both posts for voltage and both are hot when the water heater is turned off and only the post where the shore power is coming in is hot when the button for the water heater is pushed in. That component appears to be a breaker that resets itself when the excessive current is corrected. Never heard of such, but may be.

Sounds like that is some kind of self-resetting fuse. ABYC doesn’t really permit those, since any reason for a fuse blowing should be investigated and remediated before power is restored. If that’s what it is it’s not original, so an original Catalina wiring diagram won’t tell you much.

I have suspected one of my two house batteries is going out. I'll be checking that tomorrow.

Battery chargers are current limited internally. They won’t dump any more power into a bad or shorted battery than they are rated for, and they’ll put that same amount of energy into a battery at a low state of charge. Maybe your battery is bad but that’s not the root cause here. I’d still be looking at something in the water heater element circuitry for a short.

 

[Stu Jackson]

You can grt a wiring diagram from the C30 Boat Owners Manual through these skippers. They made over 6,700 Catalina 340s, the manuals are out there.







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This comes from this sbo thread by weekendrken:

1992 Catalina 30

Also: www.catalina30.com

 

[Davidasailor26]

You can grt a wiring diagram from the C30 Boat Owners Manual through these skippers. They made over 6,700 Catalina 340s, the manuals are out there.

With the substantial caveat that an exceedingly small percentage of those 40 year old boats probably have wiring that still matches the factory configuration. Without knowing anything about what previous owners may have done, and if there really was a self-resetting fuse added, I’d start tracing wires and building my own diagram before believing the OEM one.

 

[Ed Childress]

Thank you guys for your suggestions. My water heater now works. It was a short in the heating element as I first thought and when I replaced it with a new one it worked. The reason I didn't know it worked was because the indicator light on the control panel above the map table went out when I pressed the water heater button. Had I checked the line coming from the Delay Trip to the AC panel of the boat I would have seen it was still hot. An yes, Catalina did indeed put a delay trip (the pictures below show the trip when I lower the control panel and then the back side of the trip where you can read what it is). After unplugging the battery chargers and saw the indicator light didn't come back on and I then saw the battery chargers still worked after I pressed the water heater button even though the indicator light was off (normally indication no AC power to the boat), I checked the post leading to the AC panel and saw it was hot. Bottom line is the switch labeled polarity is for the delay trip and when in the ON position power should be supplied to the panel and the indicator lights should turn on. But if the indicator lights don't come on, they may be burned out and you still are getting power to the panel. I knew one of mine was burned out and have been searching for a replacement, but didn't realize the other one also burned out. The bottom picture was taken when the first one burned out before the water heater problem.
I incluided the last photo for Joe White whos 36' Catalina is also named Sail la Vie (although he capitalizes the La).

 

[Davidasailor26]

Glad it seems to be working for you with the new element. To clarify the switches on your AC panel - the top switch is your main breaker for the panel. The “polarity” label doesn’t go with the switch, it goes with the set of lights below. The lights are there to indicate whether you have reverse polarity - a potentially dangerous condition where the hot and neutral AC wires are swapped. If the reversed light comes on your should sort out what the problem is before using AC. Faulty shore power or cables can cause that. I’ve not seen a setup like that with two normal lights. Maybe other Catalina owners could say how those should work, but I don’t think their operation should change with the heater being turned on, so if they are you might still have something amiss.

 

[Maine Sail]

Have not read the whole thread but it is very common for a failed element to do this as it can create a dead short when they fail.. No breaker on a boat should be auto re-settingas this violates the safety standards..