Foretravel Owners' Forum

Foretravel Motorhome Forums => Foretravel Tech Talk => Topic started by: floridarandy on May 06, 2018, 06:13:11 pm

Title: Water Pump Fuse Size
Post by: floridarandy on May 06, 2018, 06:13:11 pm
When we added Seelevel we moved the water pump to the pump switch on the panel. It's protected by a 7.5 amp fuse behind the panel under the bathroom sink.

For the first time since the install I ran the water pump and it blew the 7.5 amp fuse and a replacement.

I'm guessing this water pump needs a bigger fuse?  Other than the display on the Seelevel the other switch is for the gas water heater.

Thoughts?
Title: Re: Water Pump Fuse Size
Post by: red tractor on May 06, 2018, 08:12:11 pm
I thought the water pump got its power from the water pump relay in the electrical service bay. Maybe that is the problem.
Title: Re: Water Pump Fuse Size
Post by: Bill Willett on May 06, 2018, 08:22:48 pm
Always check the wiring diagram before making any changes, guessing will get you into trouble.
Title: Re: Water Pump Fuse Size
Post by: floridarandy on May 06, 2018, 08:26:06 pm
Where exactly is this relay?  And how do I check it?
Title: Re: Water Pump Fuse Size
Post by: red tractor on May 06, 2018, 08:27:41 pm
It is behind the white removable panel in the bay ahead of the water tanks
Title: Re: Water Pump Fuse Size
Post by: red tractor on May 06, 2018, 08:33:27 pm
Call me I can describe where the relay is located. 813-215-3463
Title: Re: Water Pump Fuse Size
Post by: Roger & Susan in Home2 on May 06, 2018, 08:35:17 pm
The latching relay is probably behind the white panel on the side of the bigger bay, driver's side.  There are a couple different types of latching relays.  A flat gray/white one or a round VW relay.  It switches power to the water pump when any of the current water pump momentary switch closes a ground path to the relay.  That is how they get multiple switches to turn on and off the power to the pump.  I think the circuit breaker for the water pump is behind the same white panel.

From one year to the next and model,to model there are always a few small differences. 

It is generally a good practice to leave power to the pump off if you are not using the pump.  With the power on to the pump a broken water line or fitting that leaks will trigger the pump and it will empty the tank into your coach.

Here is a way to automatically switch the pump off ...
Water Pump Timer Automatically Switches Pump Off (http://www.foreforums.com/index.php?topic=30564.0)
Title: Re: Water Pump Fuse Size
Post by: floridarandy on May 06, 2018, 09:27:45 pm
Don't think it's the relay. Looking at the Seelevel manual I noticed a code I'd seen in the panel prior to the fuse blowing:

"If a sender is unresponsive or there is an open circuit in the wiring so that the sender is not connected, the display will indicate an open circuit by showing "OPn" on the LED display."

Still not sure what to look for but continuing to read.
Title: Re: Water Pump Fuse Size
Post by: Roger & Susan in Home2 on May 06, 2018, 09:48:15 pm
If you are supplying power to the water pump via the switch on the SeeLevel panel then you need to use a relay.  The switch on the SeeLevel panel is only good for 7.5 amps.

The relay switches higher current power to the pump.  The switch engages the relay.  If it is an on/off switch then the relay probably draws power all the time the switch is on. 

This is not the same relay or the same type or relay as the latching relay.  The latching relay switches power on or off when triggered by a ground pulse.

From the SeeLevel Manual....
How to avoid damaging the display or pump switch due to excessive current:

Please be aware that the water pump switch circuit has a limitation on current draw of 7.5 amps, some large pumps can draw over 10 amps. These high drain pumps must use a relay or the display console printed circuit will overheat and damage the display permanently.
If the 12V supply line from the electrical panel does not have a 7.5 amp fuse rating, please be sure to install the supplied fuse holder with a 7.5 amp automotive style fuse inline on the +12V red wire.
WARNING: All power circuits must be fused. If a fuse is not provided with the system then it is the installer's responsibility to install a fuse with a maximum rating of 10 amps. A relay is required if more than 10 amps is needed for the pump.
 
Title: Re: Water Pump Fuse Size
Post by: floridarandy on May 06, 2018, 10:09:22 pm
It's the in-line 7.5 amp fuse, at the display panel, that is blowing.
Title: Re: Water Pump Fuse Size
Post by: wolfe10 on May 07, 2018, 08:43:06 am
Randy,

Check the amp draw for your pump's specs.  Most motorhomes are set up with a RELAY for the pump because there are multiple locations for turning the pump on/off.

If pump draw is within specs, but blowing the fuse, may need to use that circuit to close a relay with higher amp fuse and wiring "feeding the relay/pump".
Title: Re: Water Pump Fuse Size
Post by: floridarandy on May 07, 2018, 10:05:07 am
 Thanks to all. With my limited knowledge and your help it appears the issue is a 12 amp draw Flowjet pump and a 7.5 am fuse.

Solution is either a lower rates pump or a relay.
Title: Re: Water Pump Fuse Size
Post by: wolfe10 on May 07, 2018, 10:24:23 am
Blow the big bucks (listed here for $2.84) and use a 40 amp Bosch-style relay:
TE Connectivity - 1432785-1 - AgSnO Form C 12 V PI MINI-ISO Relay - Allied... (http://www.alliedelec.com/te-connectivity-1432785-1/70198785/?mkwid=sbHtfQzpM&pcrid=30980760979&gclid=EAIaIQobChMIupqrpebz2gIVilcNCh2PLwgCEAQYASABEgK1GfD_BwE)

That will be better for the pump as well, as you can size the wiring so the pump doesn't see a big voltage drop.

BTW, unlike fuses, which are sized to protect the wire, going "bigger" on a relay just means more area in the points, so they last longer.  30-40 amp relays are available at any auto parts houses.
Title: Re: Water Pump Fuse Size
Post by: Roger & Susan in Home2 on May 07, 2018, 10:48:35 am
Five including wiring harness and sockets for under $12.  Never hurts to have a few extras
Amazon.com: 5 Pack - EPAuto 30/40 AMP Relay Harness Spdt 12V Bosch Style:... (https://amazon.com/gp/product/B017VDI0GY/ref=oh_aui_search_detailpage?ie=UTF8&psc=1)
Title: Re: Water Pump Fuse Size
Post by: floridarandy on May 07, 2018, 07:13:45 pm
Perfect Brett and Roger. Seelevel protects its display with a 7.5 amp fuse. If the draw in its switches is greater than 7.5 then a relay allows needed current to pass thru without harming display. Seelevel provides this info but we missed it on the install.

Will install relay this week.

Interesting that we missed this because it was only when we opened both spigots that the draw exceeded the 7.5 amps.