Wiring the Sea Era electric toilet in Cat 30 MKIII

[Tucson Sailor]

We bought the Sea Era and purchased some gear to wire it in the boat. I ran a snake from the panel to the head. Using about 15 feet of tinned, 6 awg (per Raritan) duplex, I plan to pull the wire through. We'll mount two ring terminal posts under the port settee just aft of the head compartment. The hot and ground terminal rings crimped on the duplex will be mounted there. The hot and ground terminal rings crimped on the 14 awg pump motor & switch wire coming from the head will also be mounted there.

Concerned about the 15 amps the motor pulls (albeit briefly), it was suggested that I connect the toilet directly to the battery bank. I plan to install a 25 amp breaker switch (per Raritan) with a on/off throw switch on the power panel so I can shut the toilet off. Another set of hot terminal rings crimped on the duplex will be mounted on the breaker; one from the wire coming from the positive post on the battery. The other end is from the 15' duplex and will lead from the breaker out to the head positive post. The various terminal rings are correctly sized for the battery post, terminal posts and breaker switch.

My question is where to mount the ground wire? Should it be on the battery too? Or can it be connected from the ground terminal strip via the 15' duplex to the motor? If so, do I run only the positive cable from the battery to the breaker and that's it? What do you think of my plan? Thanks, Tim

 

[Peggie Hall HeadMistress]

That's another question for Raritan...or just ask MaineSail here...he'll know.

If it wasn't Raritan who told you to connect the toilet directly to the battery bank...iow, run a new dedicated circuit with its own separate breaker for it--whoever did gave you VERY good advice That's because ANY electric toilet needs to be on its own separate dedicated circuit, shared by nothing else--not even low voltage cabin lights--that can reduce power to the motor because low voltage will damage and eventually destroy any electric motor. Low voltage is also a leading cause of sluggish toilet discharge and other problems. So your concern about the 14 amp draw accidentally led you to seek out the information you actually needed to install it correctly. Just don't undo your accidental good luck by putting something else on that circuit!

 

[Tucson Sailor]

Thanks Peggy, to give credit where it is due, the advice to use a dedicated circuit was given by a young man at the La Jolla, California West Marine store. He helped me visualize the plan and select the supplies. No "shopping" on my part but worth the price for the advice. Unfortunately, I forgot to ask about the ground wire connection. Perhaps MaineSail is watching? Regards, Tim

 

[Tucson Sailor]

My bad, it was the Shelter Island, San Diego West Marine store. Locals will know the difference. Tim

 

[jeepbluetj]

Wow, they recommended #6 for a 15A max draw? That's mighty big wire.

Your plan is spot on. A small term strip in the port settee (fwd or above the holding tank) that you can hook the toilet to.

The other end to a dedicated breaker - NOT direct to the battery. Your feed from the battery to the panel should be at least #6 if not larger. If you have nowhere to put a breaker and must wire directly to the battery, put a fuse right at the battery.

Negative should go to whatever neg bus bar you have. It _can_ go direct to the battery if you don't have a sizable neg bus bar with sizable wiring going to it. For me? I'd install a bus bar - I have one under the chart table below the shelf where my three batteries connect as well as a smaller one at the panel. All high-current pulls are on that big bus bar. I have only 2 connections on the batteries - the feed to the A/B switch and the chargers.

I work in San Diego if you want help.

 

[Peggie Hall HeadMistress]

Thanks, Jeep...electrical is not one of my strong suits, I only know that the toilet needs to be on its own dedicated circuit.

 

[seadaddler]

My Sea Era has it'own 15 amp circuit breaker,it was a 5 amp
circuit breaker factory installed but it would pop and so changed it to 15 amp and works great.
Nick

 

[Peggie Hall HeadMistress]

Sounds more like a fuse that protects the motor from "frying" than a circuit breaker. Circuit breaker allows you to cut power to the circuit that the toilet is on...for instance, to work on the toilet, and your toilet should be on one. Your fuse doesn't do that.

 

[Tucson Sailor]

Thanks Jeep, the Sea Era manual says take the distance from the source to the head (+/- 15') and double it. So 30 feet requires a #6 wire per Raritan. So if I am installing a dedicated circuit, the techie was concerned the standard 1996 Cat 30 panel wouldn't be hefty enough to support the breaker. He advised me to connect the hot duplex wire directly from the (+)battery post to the (+)circuit breaker post and from the other (+)circuit breaker post to the (+)head wire terminal post. That makes sense to my feeble brain because I can throw the switch and shut it all off. It's connecting the ground wire that I question. Is it OK to take the (-)ground duplex wire from the (-)head wire terminal post back to the (-)ground terminal buss near the panel and call it good? Or must that ground wire run all the way back to the (-)battery post and bypassing the buss? Thanks, Tim

 

[jeepbluetj]

Ground wire to the bus? I'd guess that it's good. It depends on the wire size to the ground terminal bus from the batteries. Betcha it's enough - but you should look. You'll likely find a beefy cable from the bus to the batts. By 1996 Catalina did a much better job wiring the boats than they did back when mine was made. Since you're putting in a breaker, you've covered the most important part of having a fuse/breaker in the + side that is sized for the smallest wire in the circuit - like 15A if the pigtails off the motor are 12g. And it is very good to have the breaker as a switch for maintenance, when the switch on the head gets stuck, etc...

IMHO, the panel would be fine, the feed to the panel may be too small. Direct to the new breaker to the head won't be in any way bad - just may be more wiring. You'd want that new breaker close to where you tap into the hot side.

Generically, for the negative, I'd rather have a bus bar than a batt terminal with a big stack of connectors on it. ABYC says max 4 on a batt terminal (IIRC, from memory) But that's about 2 more than I like. Too many connectors on a terminal and I think it tends to cause the terminal to loosen easier over time.

 

[Maine Sail]

Couple of things.

#1 The head should be on the load side of the battery switch or off the "C" post but close to it. Many boats have what is referred to as a "switched bus" to avoid lug stacking the "C" post of the battery switch. Either tie into the "C" post (not really advised if you already have two wires there) or tie into the switched DC bus closest to the battery switch. Try to avoid direct connections to the battery bank except for safety items such as a bilge pump or for voltage sensing when required.

A busbar such as the Blue Sea 2127 (with a cover # 2719) can be used as a 12V DC switched bus. One wire from "C" post of battery switch to the 2127 then your "switched" loads run off the busbar. These are also good to create a negative bus for the battery bank through you may want/need more than four terminals.

#2 Within 7" of the connection to the switch or its switched busbar (your connection point to the battery where the 6GA wire needs short circuit protection) you need a fuse. This fuse can be sized to protect the wire, but only if another fuse recommended by the manufacturer is in the circuit to protect against a stalled rotor. Too large of a fuse or breaker can lead to burning out the motor if it stalls. A 30A Blue Sea MRBF fuse and fuse holder can be mounted directly to the 2127 busbar.

#3 When you get to the head, and it steps down to 14GA pigtails, I generally prefer the Blue Sea Dual Power Post. 6GA terminals generally will not fit into a 30A terminal strip so the Dual Bus gets used often for such things as solar or macerators or electric heads etc...

#4 Your 6GA negative should run back to the house bank negative bus NOT the small DC panel neg load bus located near or behind the DC panel. On most Catalina's these busbbars or terminal strips, & their feed wiring, are poorly designed for handling any sort of decent load. This is why many manufacturers (fridge makers, Espar, some electric heads, windlasses, watermakers etc..) recommend running devices back to the battery. Course anything other than a bilge pump should be "switchable". If you already have more than two or three terminals on the battery negative post you'll want to add a negative distribution busbar.

 

[jeepbluetj]

What Maine said. The dual power post was what I was thinking of, just couldn't remember what it's called.

 

[Tucson Sailor]

Thank you Gentlemen, I will require a few cups of coffee in the morning to digest your recommendations. Sounds like it boils down to go big and go safe. The boat being two hours away, I need to check the buss bar installations and there is both a Xantrex battery charger and a 1500 watt inverter installed. No complaints but, perhaps there are already too many rings on the battery posts in addition to the bilge pump and stereo wires. I appreciate your advice and will get back in a week or so when we get back to the boat. Thank you for sharing your expertise. These forums are invaluable. Cheers, Tim

 

[seadaddler]

What does your main breaker look like and is it possible to add extra breakers.
Nick

 

[Tucson Sailor]

Nick, I'll get to the boat next weekend. The 25 amp (per Raritan) breaker I puchased is designed for the panel. Thanks, Tim

 

[seadaddler]

My main panel had a breaker marked head but was 5 amp and so I changed to 15 amp
and been working great.
Nick