What cable size for Jabsco Lite Flush WC

sealegsjim

sealegsjim

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I am about to instal a Jabsco Lite Flush WC to replace existing Jabsco. Installation looks fairly simple as it is a straight swap. The instructions on the website is very good but no details of the cable size required. The only electrical info on the site is that it needs a 25amp fuse. What size cable do I need? The cable run is only a metre or so from the battery. In practical terms how do I actually wire it?
Thanks in anticipation of your help
 
pvb said:
If you download the instructions, there are minimum wiring specs.

http://www.xylemflowcontrol.com/files/58500-xxxx.pdf
Click to expand...

I used 30 amp cable on a run of about 8ft combined(there and back) but the instructions will give you the correct cable if its going to be a big run ,
I used a second small blade fuse box nearer the toilet to keep the run small , and used the fuse box toalso to install a fan and leds in back bedroom and some spare slots, and then used one size larger cable to run to main feed.
Hope helps
 
pvb said:
OK, what's "30 amp wire" then?

The point I'm making is that this is utterly meaningless. Cable sizes are specified in mm2, the notional current carrying capacity will vary according to lots of factors.
Click to expand...
Your point could have been made without the usual rhetorical reply a simply did you mean 30 amp wire would have sufficed but hey ho. we are only human
 
sealegsjim said:
I am about to instal a Jabsco Lite Flush WC to replace existing Jabsco. Installation looks fairly simple as it is a straight swap. The instructions on the website is very good but no details of the cable size required. The only electrical info on the site is that it needs a 25amp fuse. What size cable do I need? The cable run is only a metre or so from the battery. In practical terms how do I actually wire it?
Thanks in anticipation of your help
Click to expand...

The distance from the battery to the toilet should be immaterial, where are you planning to connect the wiring ? Certainly should not be to the battery. The instructions linked to in post #2 state 4mm wiring, that would be a bit OTT for a 1m run, 2.5 would be fine.
 
moomba said:
Your point could have been made without the usual rhetorical reply a simply did you mean 30 amp wire would have sufficed but hey ho. we are only human
Click to expand...

It wasn't a rhetorical reply - for you to say "30 amp wire" or "30 amp cable" is equally meaningless. Cable is specified by cross-sectional area; the current it can carry depends on lots of factors. That's why Jabsco's instructions specify cross-sectional area for the wiring.
 
30 amp was specified to err on the safe size.

The cable required to carry 30 amps will depend upon cable length and so the cross sectional area is not fixed for amperage.
 
My Jabsco Lite is connected to pre-existing wires that power the bilge pump. The toilet is about 4 metres in a straight line from the panel, so probably twice that in reality. The cable is 2.5 mm2. Been like that for years now.
 
PaulRainbow said:
The distance from the battery to the toilet should be immaterial, where are you planning to connect the wiring ? Certainly should not be to the battery. The instructions linked to in post #2 state 4mm wiring, that would be a bit OTT for a 1m run, 2.5 would be fine.
Click to expand...

Thank you for this information. I have come to the conclusion that 2.5mm will be fine. If not to the battery then where to? (pardon my ignorance) I was intending connecting it via a 25amp inline fuse
 
sealegsjim said:
Thank you for this information. I have come to the conclusion that 2.5mm will be fine. If not to the battery then where to? (pardon my ignorance) I was intending connecting it via a 25amp inline fuse
Click to expand...

It should be connected after the isolator. Do you have busbars or similar ?
 
Excellent choice of toilet. Jabsco lite flush is Very reliable.
We are live aboard and installed one 6 years ago before heading off on a retirement cruise to the Med and back.
2 of us using it 24/7 for 6 years without service and it’s still working. ( It’s now become bloody noisy, but still working)
Three times I have had to remove piss induced limescale build up (unblock / replae) the outlet pipe between the toilet and the sea cock, (the outlet pipe isn’t the toilet so can’t blame the toilet for the blocked pipe)
It is still working, but as it’s now very noisy and we will be headfing off with the boat back to the Med next summer, I will replace it with a new like for like lite flush over the winter.
 
vyv_cox said:
My Jabsco Lite is connected to pre-existing wires that power the bilge pump. The toilet is about 4 metres in a straight line from the panel, so probably twice that in reality. The cable is 2.5 mm2. Been like that for years now.
Click to expand...

I am surprised by that, unless you have a 24v boat. Jabsco recommend 8mm2 cable for an 8m run. Your bilge pump is probably only around 5A so would have been wired for somewhere around this. A 20A draw will cause a larger voltage drop on wire sized for 5A. Your toilet may work, but I suspect it will work better with heavier duty wiring.
 
CLB said:
I am surprised by that, unless you have a 24v boat. Jabsco recommend 8mm2 cable for an 8m run.
Click to expand...

The Jabsco recommendations are for the total distance from the supply to the toilet and back, so it would be 19mm for a 8m run. This is way over the top.

Your bilge pump is probably only around 5A so would have been wired for somewhere around this. A 20A draw will cause a larger voltage drop on wire sized for 5A.
Click to expand...

Impossible to calculate the current draw for the bilge pump, we don't have any indication of what the pump is. We do know that the cable in question is 2.5mm though. 12v @20a over an 8m run will suffer about 18% voltage drop, about 2.2v. Totally unacceptable.


Your toilet may work, but I suspect it will work better with heavier duty wiring.
Click to expand...

No question about it !
 
Interesting post as I am in the process of doing the same job which I hope to finish tomorrow now that my heavy duty crimp tool has arrived.

The spec for the cable is in the install manual so it should be easy to get what you need. In my case the run is about 10m to the flush pump from the battery source, so that 25mm2 required according to Jabsco. Remember that the cable run is their and back i.e. 20m in my case. I am running the cable from the 100a fuse, via a battery isolator switch, to a suitable termination block near the flush pump. From there it's a short cable to the pump via a 25a blade fuse.

I did post on PBO earlier this week about my experience so far fitting the Lite Flush. It's not a 100% direct swap as Jabsco say it is. For a start only three of the four mounting holes line up with the holes of the old manual toilet. The hoses do not connect quite as quickly nor as simply as they suggest whilst they are not in the same place as on the manual toilet. I have new hoses, so it's not so much of a problem, although the outlet hose is far from easy to connect up due to the hose on the toilet being so flimsy. It is very easy to put a kink in it as it's very thin compared to the weight of the normal discharge hose that connects to the seacock. The foot switch model I bought is slightly larger than the footprint of the manual toilet, when the foot switch is installed. That means in my case it doesn't fit in the same space as the manual toilet did, meaning I will have to modify the foot switch or it won't fit.

I bought the Lite Flush on the basis it's a direct swap, but in reality it's anything but - at least not on my boat. I will get it installed, but it's become a bit of a faff. But it's a boat - so it wouldn't be normal if it wasn't a faff!!! :) Heyho.
 
asteven221 said:
Interesting post as I am in the process of doing the same job which I hope to finish tomorrow now that my heavy duty crimp tool has arrived.

The spec for the cable is in the install manual so it should be easy to get what you need. In my case the run is about 10m to the flush pump from the battery source, so that 25mm2 required according to Jabsco. Remember that the cable run is their and back i.e. 20m in my case. I am running the cable from the 100a fuse, via a battery isolator switch, to a suitable termination block near the flush pump. From there it's a short cable to the pump via a 25a blade fuse.

I did post on PBO earlier this week about my experience so far fitting the Lite Flush. It's not a 100% direct swap as Jabsco say it is. For a start only three of the four mounting holes line up with the holes of the old manual toilet. The hoses do not connect quite as quickly nor as simply as they suggest whilst they are not in the same place as on the manual toilet. I have new hoses, so it's not so much of a problem, although the outlet hose is far from easy to connect up due to the hose on the toilet being so flimsy. It is very easy to put a kink in it as it's very thin compared to the weight of the normal discharge hose that connects to the seacock. The foot switch model I bought is slightly larger than the footprint of the manual toilet, when the foot switch is installed. That means in my case it doesn't fit in the same space as the manual toilet did, meaning I will have to modify the foot switch or it won't fit.

I bought the Lite Flush on the basis it's a direct swap, but in reality it's anything but - at least not on my boat. I will get it installed, but it's become a bit of a faff. But it's a boat - so it wouldn't be normal if it wasn't a faff!!! :) Heyho.
Click to expand...

Use the Recommended cable size which came with the instructions , this allows no issues, remember your cable run is doubled , can use single wire or 2 core cable which i did. put the fuse lower than the cable to allow protection
and there is no such thing as overkill , only over priced , if you want to use 30 amp cable or wire then its your money and to be honest the price is negative to that amount of cable , me I always err on caution.
Fitted two jabesco marine toilets (electrical) and plumbed then all to a 90 l holding tank with a pump to pump out.
Not an expert , but did my research intensively and fitted away , no issues no leaks , no blown fuses. and if gets rid of my mess, then its working full power:encouragement:
 
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