Go Back   Train Horn Forums > Installation Help & Advice > Miscellaneous
 Register

Reply
 
Thread Tools Display Modes
  #1  
Old 31st October 2014
rccrazy30 rccrazy30 is offline
Junior Member
 
Join Date: August 2013
Posts: 7
rccrazy30 is on a distinguished road
Default Electrical issues

Ok so ive had this an air system installed on 2 trucks 450C on a 5gallon tank. On monday i went to leave work and i got a "service charging system" warning so i had the battery and alternator checked all good. so the only thing i got drawing off the battery is the compressor. so i started looking at that i found my connector got obviously HOT on both ends so im thinking something is wrong with the compressor i ran the system all summer pretty much daily without any issues. i will also add the tank and compressor are in a tool box thats covered. I also found that i was using a probably too light of a gauge main power was on a 12g according to the chart i should have used 10g so ill be changing that... but that still doesn't answer the question of why it has worked thus far without issue.
Reply With Quote
  #2  
Old 31st October 2014
rjk rjk is offline
Senior Member
 
Join Date: May 2014
Location: Ohio
Posts: 114
rjk is on a distinguished road
Default Re: Electrical issues

The longer your wire, the fatter it needs to be. 12 sounds real small for a pump.

The warning could be due to an alternator that is about to fail but hasn't yet, or any number of other problems that might be hard to diagnose because of all the computer systems in trucks these days.
Reply With Quote
  #3  
Old 31st October 2014
rccrazy30 rccrazy30 is offline
Junior Member
 
Join Date: August 2013
Posts: 7
rccrazy30 is on a distinguished road
Default Re: Electrical issues

Quote:
Originally Posted by rjk View Post
The longer your wire, the fatter it needs to be. 12 sounds real small for a pump.

The warning could be due to an alternator that is about to fail but hasn't yet, or any number of other problems that might be hard to diagnose because of all the computer systems in trucks these days.

Yeah but like i said ive been using 12 for the past 2 years without issue. although for safety im redoing it to 10g im only running one pump @ 20amps. I have it after the mega fuse on the battery. is that correct? im thinking i should add a separate fuse at the battery i have one at the relay/pressure switch
Reply With Quote
  #4  
Old 31st October 2014
rjk rjk is offline
Senior Member
 
Join Date: May 2014
Location: Ohio
Posts: 114
rjk is on a distinguished road
Default Re: Electrical issues

The fuse is there only to protect the wire. Think of it this way - if the wire shorts out and there is no fuse or if it is too big, the wire will burn because the battery is essentially a source of unlimited current (usually more than 3000 amps surge). The best place for the fuse is as close to the battery as you can get. If you have smaller control wires, they should have their own smaller fuse.

What's the amp rating for your compressor? Sorry I don't have a spec sheet in front of me.
Reply With Quote
  #5  
Old 31st October 2014
rccrazy30 rccrazy30 is offline
Junior Member
 
Join Date: August 2013
Posts: 7
rccrazy30 is on a distinguished road
Default Re: Electrical issues

Quote:
Originally Posted by rjk View Post
The fuse is there only to protect the wire. Think of it this way - if the wire shorts out and there is no fuse or if it is too big, the wire will burn because the battery is essentially a source of unlimited current (usually more than 3000 amps surge). The best place for the fuse is as close to the battery as you can get. If you have smaller control wires, they should have their own smaller fuse.

What's the amp rating for your compressor? Sorry I don't have a spec sheet in front of me.
makes sense ill have to add a fuse closer to the battery.

according to the spec sheet it draws 19amps
Reply With Quote
  #6  
Old 31st October 2014
rjk rjk is offline
Senior Member
 
Join Date: May 2014
Location: Ohio
Posts: 114
rjk is on a distinguished road
Default Re: Electrical issues

Here's a good chart: http://assets.bluesea.com/files/reso...lection_lg.jpg
If your wire is 15 feet or less, 10 awg should be good. Make sure the crimps are on solid - that's another source of heat if they are loose.
Reply With Quote
  #7  
Old 31st October 2014
rccrazy30 rccrazy30 is offline
Junior Member
 
Join Date: August 2013
Posts: 7
rccrazy30 is on a distinguished road
Default Re: Electrical issues

Quote:
Originally Posted by rjk View Post
Here's a good chart: http://assets.bluesea.com/files/reso...lection_lg.jpg
If your wire is 15 feet or less, 10 awg should be good. Make sure the crimps are on solid - that's another source of heat if they are loose.
15ft should be enough. i try to soldier and shrink rap as much as possible.


im wondering what would cause the pump to all of a sudden draw more current then it has in the past
Reply With Quote
  #8  
Old 31st October 2014
rjk rjk is offline
Senior Member
 
Join Date: May 2014
Location: Ohio
Posts: 114
rjk is on a distinguished road
Default Re: Electrical issues

I doubt it has changed much, but loose connectors will make amp draw go way up because they reduce the voltage to the compressor. It's also possible that the wire has run hot but you didn't notice since it was working.

With the bigger wire you will also have less voltage drop, which means the compressor might even run a little faster and fill your tank in less time.
Reply With Quote
  #9  
Old 1st November 2014
surrealone surrealone is offline
Senior Member
 
Join Date: April 2013
Posts: 286
surrealone is on a distinguished road
Default Re: Electrical issues

In addition to keeping the fuse as close to the power source as possible, a general rule of thumb for safety is to upsize the wire by one gauge for the run you're doing if you're close to the maximum rated amperage on the wire for that length of wire.

Thus, if you're close to 20 amps at 15 feet using 10gauge, move up to 8 gauge.

Also, make sure you're using pure oxygenated copper wire, as copper clad aluminum, while cheaper, is also less conductive. If your only option is copper clad aluminum due to cost reasons, then upsize the gauge yet again.
Reply With Quote
  #10  
Old 1st November 2014
ear2ear's Avatar
ear2ear ear2ear is offline
Moderator
 
Join Date: December 2009
Location: Middle, USA
Posts: 3,182
ear2ear is on a distinguished road
Default Re: Electrical issues

Quote:
Originally Posted by rccrazy30 View Post
15ft should be enough. i try to soldier and shrink rap as much as possible.


im wondering what would cause the pump to all of a sudden draw more current then it has in the past
Check your grounds. Make sure you have bare shiny metal. A ground with some corrosion will draw more amperage. That would explain the change. It was probably gradual.

EDIT: As mentioned above the fuse should be placed close to the power source. BUT, it has to be sized correctly. It must be rated smaller than the rating of your wire gauge & length. For example if the wire was rated for 20 amps and you had a 30 amp fuse, the wire would melt before the fuse blows. You want the fuse to blow FIRST.

Last edited by ear2ear; 1st November 2014 at 05:19 PM.
Reply With Quote
Reply

Thread Tools
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

Forum Jump


All times are GMT -4. The time now is 04:21 PM.