Return to the home page...

Go Back   Moyer Marine Atomic 4 Community - Home of the Afourians > Discussion Topics > Ignition System

Reply
 
Thread Tools Display Modes
  #1   IP: 24.152.132.65
Old 11-10-2016, 08:23 AM
ndutton's Avatar
ndutton ndutton is offline
Afourian MVP
 
Join Date: May 2009
Location: Torrance, CA
Posts: 9,617
Thanks: 197
Thanked 2,204 Times in 1,424 Posts
As I've preached before . . .

Following the addition of a second electric coolant pump I remeasured the alternator output and coil input voltages (ahead of the ballast resistor) to recalculate voltage drop. With the added load I've crept up to 5% so some engine harness work is added to the project list.

Besides staying on top of the ignition wiring as loads are added, I was directed to make the check by the EWDS. Ignition on before pushing the start button I was getting a coil indicator light, no light when running though.

My current harness is over 15 feet long, hot (red) wire to the panel is 12 gauge, starter solenoid wire (white) back to the engine is 12 gauge and the ignition wire (purple) is 12 gauge. Looks like I'll be replacing those three with 10 gauge.
__________________
Neil
1977 Catalina 30
San Pedro, California
prior boats 1987 Westsail 32, 1970 Catalina 22
Had my hands in a few others
Reply With Quote
The Following 2 Users Say Thank You to ndutton For This Useful Post:
Administrator (11-10-2016), BobMcD (11-14-2016)
  #2   IP: 24.152.132.65
Old 11-26-2016, 05:52 PM
ndutton's Avatar
ndutton ndutton is offline
Afourian MVP
 
Join Date: May 2009
Location: Torrance, CA
Posts: 9,617
Thanks: 197
Thanked 2,204 Times in 1,424 Posts
Engine harness rework complete and tested

With the larger 10 gauge wire for hot (red) and ignition (purple), measured voltages are now:
Alternator output → 14.0V
Coil input ahead of resistor → 13.6V

VDrop% = [(Valt - Vcoil)÷ Valt] x 100
VDrop% = [(14.0V - 13.6V) ÷ 14.0V] x 100
VDrop% = [0.4V ÷ 14.0V] x 100
VDrop% = 0.0286 x 100
VDrop% = 2.9% (Target drop is 3% or less)

Total ignition system current:
Ignition --------------------------3.24A
Facet fuel pump ----------------1.6A
Two coolant pumps @ 2.2A --- 4.4A
9.24A total, necessary to know so the ignition circuit fuse is sized properly

edit:
I should have mentioned it in the first post, original measurements were:
Alternator output → 14.0V
Coil input ahead of resistor → 13.2V
5.7% Voltage drop

The purpose of this thread is to present a real world example of voltage drop and how easily it is [properly] resolved.

edit 2:
I re-ran the EI calculation with the improved voltage too, 3.24A (3.3Ω coil + 0.885Ω resistor)
Target amperage is less than 4 amps, I arbitrarily prefer 15% less for a target of 3.4 amps max.
__________________
Neil
1977 Catalina 30
San Pedro, California
prior boats 1987 Westsail 32, 1970 Catalina 22
Had my hands in a few others

Last edited by ndutton; 11-27-2016 at 10:40 AM.
Reply With Quote
The Following 2 Users Say Thank You to ndutton For This Useful Post:
Administrator (11-26-2016), Bratina (11-27-2016)
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 01:34 AM.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2024, vBulletin Solutions, Inc.


Universal® is a registered trademark of Westerbeke Corporation

Copyright © 2004-2024 Moyer Marine Inc.

All Rights Reserved