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Replacing NS-12P with SAR V3

PostPosted: Fri Feb 18, 2011 8:34 am
by ovasek
When I was replacing batteries my NS-12P( that I had for 10 years) failed and when I installed my spare NS-12P, it failed almost immediately developing the same symtoms as the original regulator. The symptoms were that when the regulator turn ON it charged for approximately 6 seconds and then the red light indicated “ no battery reference voltage” all voltages and ground connections appeared to be normal and only potential problem I found was broken wire on snubber diode on one alternator creating intermittent connections. I also replaced fuse holder on battery reference voltage wire which might have intermittent connection .
I have sent 2 defective regulators for repair but do not have any report what caused the malfunction. When I talked to Ruth in your office she could not tell me when someone will look at my regulators. I decided to upgrade to SAR V3 regulator, I cannot operate my boat without properly charging batteries.
I have two AMPTECH PT-43 alternators mounted on one engine connected in parallel charging 8 Trojan T-105 batteries hooked up in series- parallel combination to form 12 V bank. I also have EMON II – H1 . Alternator filled wires have circuit breakers which are used to turn off one of the alternators during the start up to allow engine to get out of idle.
I have the following questions to prevent potential damage to my new SAR V3 regulator

1. What are the proper settings for SAR V3 using Trojan T-105 batteries (thick or thin plates?)
2. Are there any special settings on EMOM II
3. The alternators have snubber diodes , should there be some surge protection on field circuits to prevent damage when switching circuit breakers or is there protection built in SAR V3
4. I have temperature sensors that were used with NS-12P, could they be used with SAR V
5. What is the proper hookup and settings for equalization.
Thank-you, for your prompt response

Re: Replacing NS-12P with SAR V3

PostPosted: Sat Feb 19, 2011 2:06 pm
by Coulomb
DO NOT put circuit breakers in the field wires. If you want to disable the alternators, turn off the Ignition, (On/Off) input.

A broken wire on a snubber may indicate that alternator output was interrupted when running. Do you have alternator charge current going through a battery selector switch. That could explain why your Next Step Regulators let the smoke out. See this URL:

Use Medium Thickness for Trojans.
The Emon has no changes required.

Equalization is a dangerous procedure if done by someone who doesn't know how to do it. The SAR V3 manual tells you the mechanics of what to do, but you need to do some homework on the subject of equalization. The book "Living on 12 Volts with Ample Power" explains what the process is.

Perhaps someone with no legal liability will offer step-by-step instructions.

Re: Replacing NS-12P with SAR V3

PostPosted: Mon Feb 21, 2011 11:28 am
by ovasek
There are no switches or isolators in the charge circuit.
What would be recommended way to selectively turn on alternator one or two or both. The circuit barkers were in the field as the original boat wiring ,is it better to eliminate them and and them and turn ignition on off to allow engine to get out of idle .
I am familiar with equalization I have done it for past 10 years and at the time of writing I did not have V3 installation instruction and if I understand correctly B+ voltage for at least 2 sec. to Equal. terminal should start the equalization.
Thank you Vince

Re: Replacing NS-12P with SAR V3

PostPosted: Tue Feb 22, 2011 7:08 pm
by Coulomb
Why are you concerned about the engines at idle? The alternators won't be producing any power at that RPM, so they won't be loading the engine. How much horse power do you have?

Remove the circuit breakers from the field wires and use a couple of toggle switches to turn the regulators on and off.

Re: Replacing NS-12P with SAR V3

PostPosted: Mon Feb 28, 2011 5:00 pm
by ovasek
I have 60HP Yanmar engine and according the power curve it has 8HP at idle speed and if batteries are discharged it does not have power to get out of the idle. I have solved the problem using the limit switch.
Regulator seams to operate normally except the equalization , when it starts by applying B+ voltage to the equalization enable, voltage rises to 16.2 volts and after abut a minute it goes back to 13.8 . I have turned the second limit pot 20 turns CW but no change.
Anything to check or adjust?

Re: Replacing NS-12P with SAR V3

PostPosted: Wed Mar 02, 2011 8:51 pm
by Coulomb
You turned the Amps all the way up. You need to start on the other end and bring up Amps slowly to the desired equalization current.