Reply
 
Thread Tools Search this Thread Display Modes
 
Old 09-03-2015, 12:45 PM   #1
2 Rivet Member
 
tlundell's Avatar
 
2015 Interstate Ext. Coach
Los Gatos , California
Join Date: Sep 2014
Posts: 63
7.5 amp fuse in 12v refer ciruit keeps blowing

In the 2015 Grand Tour, the refrigerator and freezer share a 12v circuit for non-shore power use. Recently the 7.5 amp fuse has blown on three separate occasions, though I'm not sure at what point that occurs (e.g., turning on the appliances while not connected to shore power or disconnecting shore power while they are already running). This was not a problem earlier on, so not sure why it has developed all the sudden. Simple or complex problem?
__________________

__________________
Tim
2015 Interstate Grand Tour
WBCCI Member #5506
tlundell is offline   Reply With Quote
Old 09-03-2015, 01:48 PM   #2
2 Rivet Member
 
2015 Interstate Ext. Coach
New Orleans , Louisiana
Join Date: May 2015
Posts: 33
After looking up the current draw for the refrigerator and the freezer in the manual (12 amps) I replaced the 7.5 with a 15. It hasn't blown and the coach hasn't burned to the ground. As a bit more reassurance on page 5-18 of the 2015 manual it lists Circuit 6 for the Grand Tour (on right side) as 15 amp, Red. I think they messed up the panel labels on the coach itself.

The only other workaround I found was to make sure the inverter is on whenever the fridge and freezer are on, since they run by preference (unintuitively) on 110 AC.
__________________

__________________
NOLA_russ is offline   Reply With Quote
Old 09-03-2015, 02:14 PM   #3
Rivet Master
 
73shark's Avatar
 
2011 Interstate Coach
Overland Park , Kansas
Join Date: Aug 2011
Posts: 2,748
If your frig and freezer are like the Novakool in the non-Grand Tour, then running on the inverter uses more power not only the inverter itself, but the frig converts the 110 VAC to 12 VDC to run on. So unless you're on shore or generator power, it's more efficient to run w/o the inverter unless, of course, you need the inverter for something else.

Someone actually unplugged the AC line so it always runs off the house battery.
__________________
Glass half full or half empty to an engineer is the glass is twice as big as it needs to be.

PM me for sale info on my 2011. SOLD!
Upfitted Transit 350 sitting in driveway.
73shark is offline   Reply With Quote
Old 09-03-2015, 03:57 PM   #4
Rivet Master
 
Boxster1971's Avatar

 
2013 Interstate Coach
Fulton , Maryland
Join Date: May 2010
Posts: 2,269
I was one of those that unplugged my refrigerator AC plug. The wiring diagram I received from Airstream shows the refer AC to be on a shore power circuit, but that is not how mine was wired. It had the AC for the refer coming from the inverter. So that placed an additional load on the inverter that made no sense. I just disconnected the AC cord so the refer always runs directly fro the 12V house battery.


- - Mike
2013 Interstate Lounge EXT on 2012 Sprinter
__________________
- - Mike
--------------------------
2013 Airstream Interstate Lounge EXT
Boxster1971 is online now   Reply With Quote
Old 09-03-2015, 04:58 PM   #5
Rivet Master
Commercial Member
 
lewster's Avatar
 
Vintage Kin Owner
Naples, FL , Hood River, OR
Join Date: Dec 2005
Posts: 7,282
I would NOT upgrade any fuse without knowing the wire size coming from that fuse position. You are fusing to protect the WIRE, not the device!!


Lew Farber
RVIA/RVDA Nationally Certified Master Tech
Master Tech Energy Systems, Inc.
AM Solar Certified Installation Center
Lifeline Batteries**Magnum Inverters
541-490-6357
__________________
Lew Farber...ABYC Certified Master Marine Electrician...RVIA Certified Master Tech ...AM Solar Authorized Installation Center...AIRSTREAM Solar & Electrical Specialist...Micro Air 'Easy Start' Sales and Installations
lewster is offline   Reply With Quote
Old 09-03-2015, 09:49 PM   #6
Figment of My Imagination
 
Protagonist's Avatar
 
2012 Interstate Coach
From All Over , More Than Anywhere Else
Join Date: Dec 2011
Posts: 10,329
Quote:
Originally Posted by tlundell View Post
In the 2015 Grand Tour, the refrigerator and freezer share a 12v circuit for non-shore power use. Recently the 7.5 amp fuse has blown on three separate occasions, though I'm not sure at what point that occurs (e.g., turning on the appliances while not connected to shore power or disconnecting shore power while they are already running). This was not a problem earlier on, so not sure why it has developed all the sudden. Simple or complex problem?
According to my owner's manual, the fuse for a non-Grand Tour Interstate is 8 amps to run ONE Nova Kool refrigerator/freezer. I suspect that to run two units simultaneously creates more load than your 7.5-amp fuse can handle. But as Lewster points out, there's no guarantee that your wire gauge for that circuit isn't too small as well, so simply going to a larger fuse isn't necessarily a fix. Starting an electrical fire because you're tired of blowing fuses is a case of the cure being worse than the disease.

As for why it developed all of a sudden, it could be air temperature related. Two Nova Kool units running together generate a lot of heat at the coils, and if the temperature of the air around those coils is already hot, there's no place for the heat in the coils to go. This means that your units run inefficiently, more so than they do in cooler weather when there's a proper temperature gradient between coils and air. If possible, park so that the side of the van where the Nova Kools are is in the shade to minimize heat transfer from outside, and open a cabinet door or drawer to allow air-conditioned air to get into your galley cabinets around the Nova Kools.
__________________
WBCCI #1105
TAC LA-4

My Google-Fu is strong today.
Protagonist is online now   Reply With Quote
Old 09-03-2015, 11:00 PM   #7
2 Rivet Member
 
tlundell's Avatar
 
2015 Interstate Ext. Coach
Los Gatos , California
Join Date: Sep 2014
Posts: 63
As has been pointed out, the fuse panel is contrary to the most recent Owners Manual, which, for both the 2015 and 2016 model GT's, show a 15 amp fuse for the refer circuit, with the load chart showing 8.62 amps at 12v. Understand about not taking risk by substituting higher rated fuse (how about just inching up to a 10 amp?), but how to reconcile documentation with the actual setup?
__________________
Tim
2015 Interstate Grand Tour
WBCCI Member #5506
tlundell is offline   Reply With Quote
Old 09-04-2015, 12:42 AM   #8
Rivet Master
Commercial Member
 
lewster's Avatar
 
Vintage Kin Owner
Naples, FL , Hood River, OR
Join Date: Dec 2005
Posts: 7,282
For a DC run from the fuse panel to your fridge connection, you would need 14AWG wires for a 15 amp fuse, and 16AWG wires for a 10 amp fuse.

You can always use a smaller fuse than the current carrying capacity (ampacity) of a wire......but not a larger one. On newer Airstream trailers, I regularly see 15 amp fuses used on all of the 12AWG circuits, which are rated to use 20 amp fuses. Older trailers have the 20 amp fuses on the same 12AWG DC wires.
__________________
Lew Farber...ABYC Certified Master Marine Electrician...RVIA Certified Master Tech ...AM Solar Authorized Installation Center...AIRSTREAM Solar & Electrical Specialist...Micro Air 'Easy Start' Sales and Installations
lewster is offline   Reply With Quote
Old 09-04-2015, 01:13 AM   #9
Rivet Master

 
2007 22' International CCD
Corona , California
Join Date: Jul 2013
Posts: 3,322
Verify the size of the wire to the fridge is at least 14 gauge. Then a 15 amp fuse is fine.


Sent from my pocket Internet using Airstream Forums
__________________
KE4GNK/AE
'The Silver HamShack' (2007 International 22FB CCD 75th Aniversary model)
Multiple Yaesu Ham Radios inside and many antennae sprouting from roof, ProPride hitch
2012 shortbed crewcab 4x4 Toyota Taco TV with more antennae on it
rmkrum is online now   Reply With Quote
Old 09-04-2015, 10:28 AM   #10
2 Rivet Member
 
2015 Interstate Ext. Coach
New Orleans , Louisiana
Join Date: May 2015
Posts: 33
The wire from the fuse panel is the same gauge as the other 15 and 20 amp circuits, and larger than the 5 amp circuit. I'll leave it to someone else to pull apart their interior to verify the full circuit is 14 gauge. Given the circuit diagram and manual agree it's 15 amp, combined with the load from the refrigerator, freezer, and propane valve far exceeding 7.5 amp, and the fact that I changed this months ago and have used it heavily since, I'm assuming the panel is mislabeled. If others are more risk averse just make sure the inverter is on before you turn on the fridge and freezer when disconnected from shore power or buy a lot of 7.5a fuses.

Of course you can also have your dealer's service department sort it out.
__________________

__________________
NOLA_russ is offline   Reply With Quote
Reply

Tags
12v


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
12v 20A circuit keeps blowing blade fuse rayandre Lights - Interior & Exterior 1 08-08-2013 07:04 AM
Generator 20 amp fuse keeps blowing jtsanchez Generators & Solar Power 6 02-13-2013 11:48 AM
power jack keeps blowing fuse? jlemmons Jacks, Stabilizers, Lifting and Leveling 6 08-01-2009 11:38 AM
Fuse #1 keeps blowing Z33 Electrical - Systems, Generators, Batteries & Solar 12 12-16-2006 09:43 AM
Brake Light fuse keeps blowing BW_LandYacht36MH Land Yacht/Legacy Motorhomes 3 08-25-2005 01:25 PM


Virginia Campgrounds

Reviews provided by




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 11:34 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.

Airstream is a registered trademark of Airstream Inc. All rights reserved. Airstream trademark used under license to Social Knowledge LLC.