Electric heads installation

[seansea]

I have fitted a Jabsco electric heads which fits fine in place of the manual one. Now to the wiring. I was proposing to feed into the shower pump which is a low current draw. It would be extremely difficult to run a new supply being as the heads is near the forward end of the boat on opposite side to the DC nav panel so what is the best way to join the electric heads to the shower sump cable? I know there are all kinds of connectors but not sure if they are suitable in a marine environment. Can I use a chocolate box with liquid electrical tape?

 

[burgundyben]

Will the circuit breaker or fuse for the shower pump and its wiring be up to the job?

Shower pump maybe 2 amps?

New bog pump more like 20 amps?

 

[SiteSurfer]

I've just done this, and detailed it in a video.
The instructions for our heads said that we should connect using a specific gauge cable, I subsequently wired in a relay to the switch panel - and then the correct gauge cable to the heads in order to avoid voltage drop and (also) trying to avoid piggybacking on to other appliances which may have then overloaded the cable.

It was pretty painless. I think that the task of running a couple of 10 AWG cables rather less then a burnt out circuit or the inability to isolate the electric heads.

If its of any use whatsoever, fat bloke installing an electric heads - I touch on the cabling briefly and how I distributed it.

 

[VicS]

I have fitted a Jabsco electric heads which fits fine in place of the manual one. Now to the wiring. I was proposing to feed into the shower pump which is a low current draw. It would be extremely difficult to run a new supply being as the heads is near the forward end of the boat on opposite side to the DC nav panel so what is the best way to join the electric heads to the shower sump cable? I know there are all kinds of connectors but not sure if they are suitable in a marine environment. Can I use a chocolate box with liquid electrical tape?

If you do use chocolate box connectors make sure they are all brass inside ... no steel to rust and use the type where the grub screws do not bear directly on the wiring. ( unless you are also going to fit bootlace ferrules .)

Wago connectors seem to be more popular with forum members but I have no personal experience of using them

Also as queried above is the wiring intended for a low current draw shower pump heavy enough for the Jabsco toilet without suffering excessive volts drop .... The 12 volt Jabsco draws 16 amps

 

[PaulRainbow]

It's going to be extremely unlikely that the shower pump wiring will be rated for the toilet. Shower pumps are invariable wired with 2.5mm cable, sometimes 4mm, depending on the length of cable run. Most 12v Jabsco bogs will be fitted with 25a fuses and will require much fatter cable, depending on the length of the OPs boat, 6mm to 8mm sq. If you use under rated cables with a macerator bog, like the Jabsco, the first sign of anything solid and the pump will stall and you will be in the proverbial.

I wouldn't use choc block connectors.

 

[FlyingGoose]

Having fitted 2 of these toilets fore and aft. everything Paul says I also did . both on 30 amp cable and protected by 25 amp fuses .

 

[superheat6k]

I have just fitted a similar to Jabsco electric loo base, and followed the maker's recommendations to run the cables in 10mm2 out from the distribution panel MCB and back to the nearest engine block negative, except the last couple of feet from the switch (~15m round run). I also used crimped, soldered and double heatshrunk the joints to ensure a strong and vibration proof joint at the point where the 10mm2 reduces to 2.5mm2 near the loo.

Haven't been able to test it yet except a brief blip start as my boat is high and dry for at least another week.

 

[simonfraser]

you may be able to use the current cables to pull the bigger ones through.
if you do so, make sure they are attached firmly to each other and run a mouse wire at the same time.

 

[PaulRainbow]

you may be able to use the current cables to pull the bigger ones through.
if you do so, make sure they are attached firmly to each other and run a mouse wire at the same time.

That would be a good solution.

I'd pull 10mm cables through, connect the positive to a double blade fuse holder in the heads, with fuses rated for each pump. Then run separate cables to the heads and shower pump. The fuse/breaker at the panel could be rated for the combined current draw of the two pumps, plus a bit for good measure, say 40a.

 

[VicS]

Having fitted 2 of these toilets fore and aft. everything Paul says I also did . both on 30 amp cable and protected by 25 amp fuses .

30 amps cable is nowhere near heavy enough for a toilet that draws 16 amps unless they are very, very short .......... like no more than about 3.5 metres total positive + negative.
Voltage drop in the cables significantly longer than that will affect the performance of the pump.

That is why 10mm ² ( 70 amp ) cable is recommended

 

[FlyingGoose]

30 amps cable is nowhere near heavy enough for a toilet that draws 16 amps unless they are very, very short .......... like no more than about 3.5 metres total positive + negative.
Voltage drop in the cables significantly longer than that will affect the performance of the pump.

That is why 10mm ² ( 70 amp ) cable is recommended

Thanks for the recommendation , I Have them on separate fuse holders hubs around 2 metres away from each toilet which in turn are then connected back to the main power feed at my navigation station(centre of boat also fused) the wire leading to the fuse holders is heavy enough to take the load on the toilets and some new led lights that I installed . seems good after 2 years with no loss of suction on my Poo Poos I get around 3% voltage drop.
Sorry if that was not explained

 

[seansea]

Will the circuit breaker or fuse for the shower pump and its wiring be up to the job?

Shower pump maybe 2 amps?

New bog pump more like 20 amps?

I believe 2 amps is correct for the shower pump rating and heads is rated at 1 amp/hr per day.

 

[PaulRainbow]

I believe 2 amps is correct for the shower pump rating and heads is rated at 1 amp/hr per day.

Quoting an amp/hour figure for the toilet is meaningless. It's like saying your car has a top speed of 120 miles per day.

Your toilet will have a current rating of circa 16a max. That means if you run it for one hour, it will have used 16ah. To only use 1 a/h in a day isn't going to give you many flushes. But, a/h has no bearing on the cables you will require, that's down to current draw and voltage drop.

 

[VicS]

Quoting an amp/hour figure for the toilet is meaningless. It's like saying your car has a top speed of 120 miles per day.

Your toilet will have a current rating of circa 16a max. That means if you run it for one hour, it will have used 16ah. To only use 1 a/h in a day isn't going to give you many flushes. But, a/h has no bearing on the cables you will require, that's down to current draw and voltage drop.

Thats not a good explanation. 120 miles per day is a perfectly valid , although very slow , speed It is in fact equal to 5 mph. ( about right for the top speed of a wheel barrow)

The expression" 1 amp/ hr per day" is a nonsense expression

If, however, seansea had said 1 Ah per day it would have been a valid expression .
In fact if a 16 amp toilet pump is operated for a few minutes in total every day it would be using about that much

 

[Norman_E]

I don't know what boat the OP has, but I suggest he looks behind the DC switch panel to see if there is a conduit with a draw string or wire to enable him to get the appropriate sized cables forward. The alternative is to diconnect the shower pump cables and use them to pull in suitable cable to supply both the heads and the shower drain pump. He will need to fit a heavier circuit breaker or fuse at the panel.

 

[seansea]

I believe 2 amps is correct for the shower pump rating and heads is rated at 1 amp/hr per day.

Thanks for the feedback. I was quoting directly form the description on Force 4's listing (see attached) but as you've pointed out it's incorrect and I had my doubts at the time over this. How do you arrive at 16 amp toilet?

I will have to rethink the installation and run new cable through. The alternative is to put the electric heads aft (2 heads on boat) which is what I could have done in the first place with hindsight had I realised what I know now!

 

[VicS]

Thanks for the feedback. I was quoting directly form the description on Force 4's listing (see attached) but as you've pointed out it's incorrect and I had my doubts at the time over this. How do you arrive at 16 amp toilet?

I will have to rethink the installation and run new cable through. The alternative is to put the electric heads aft (2 heads on boat) which is what I could have done in the first place with hindsight had I realised what I know now!

It is the standard Jabsco electric toilet that takes 16 amps ..... That info can be found in the description on the Jabscoshop web site

Butt you did not say you were fitting the Jabsco Lite Flush toilet .. I guess everyone assumed you were fitting the standard one. A somewhat less expensive option.

The description on the Jabsco shop website of the Lite Flush has the same meaningless expression as you have found on the Force4 website

A 25 amp fuse is specified for both toilets so that's a pretty good clue that they will draw a similar, if not the same, current.

 

[vyv_cox]

I cannot recommend the Lite Flush for long-term use. I owned one for several years and every year spent hours with it in pieces. You could check the internet for reviews: there are many very negative ones. In principle it is quite good but carbonate salts are its downfall. One of its plus points in the sales literature is the small volume of water used to flush, desirable with closed holding tanks. This feature leads to massive deposition inside the macerator pump, which in turn leads to belt failures (not actually a problem with mine). Joker valves and discharge hose foul very rapidly for the same reason. In the end the impeller needed to be replaced but I could only buy the complete pump and motor assembly, for twice the price of a new Twist 'n Lock manual toilet. Which was what I bought.

 

[Cantata]

I went through all this last year, eventually fitted a Dometic Masterflush 7220 loo. It was the only one available with a low enough overall height to fit in position. Been very pleased with it, it cost less that equivalent Jabsco's (they wouldn't have fitted anyway), and it's very quiet indeed, much much quieter than the Jabsco we had in our prevous boat. Wiring? I just followed their instructions, took whatever the amp rating was and added quite a bit to make sure.

 

[seansea]

I cannot recommend the Lite Flush for long-term use. I owned one for several years and every year spent hours with it in pieces. You could check the internet for reviews: there are many very negative ones. In principle it is quite good but carbonate salts are its downfall. One of its plus points in the sales literature is the small volume of water used to flush, desirable with closed holding tanks. This feature leads to massive deposition inside the macerator pump, which in turn leads to belt failures (not actually a problem with mine). Joker valves and discharge hose foul very rapidly for the same reason. In the end the impeller needed to be replaced but I could only buy the complete pump and motor assembly, for twice the price of a new Twist 'n Lock manual toilet. Which was what I bought.

Bit late now. Oh well, it looks like short term use then and finding a way to reduce calcium deposits. I overlooked the fact it was low water usage which is not a selling point but it is better looking which is now a marginal positive.