L

laz

Well Known Member
I was doing some checks on my RV8 electrical system that I just finished a few weeks ago. This is a brand new plane under construction. Before I fired up any of the Garmin G3x stuff, I tested the usual systems , starter , fuel pump lights etc. all seemed to work fine. I fired up the G3x and it also come on line with no problems.

Yesterday I had everything on line and tested the starter again. When the starter turned all my other electronics died. As soon as the starter stopped they came back on. It appears that the current draw from the starter took the voltage available to the other Items so low they shut down ( most of the G3X stuff shuts down below 11 volts or so). I have a new odyssey battery 680 and it appears to be charged. Here are my questions.

1. Battery solenoid gets warm with the battery master on. Is this normal?

2. Could this be a battery issue?

3. What test can I perform on the solenoid, battery etc. ?

Thanks
 
(1) yes
(2) possibly a low battery
(3) if it was your solenoid I would doubt you could start engine, check the volts and cold cranking amps on your battery with an amp meter. I doubt your problem isn't something many have encountered. I have back up batteries on the electronics and I assume they prevent them from shutting down.
 
laz said:
1. Battery solenoid gets warm with the battery master on. Is this normal?

2. Could this be a battery issue?

3. What test can I perform on the solenoid, battery etc. ?

Thanks
Click to expand...

Any of these could be the problem, plus others.

A PC-680 is not invincible. Some panels these days draw in excess of 20 amps. This means a PC-680 will be flat in less than an hour. Before you get too deep into troubleshooting, put a charger on the battery with the master off. Keep a volt meter on the battery to monitor terminal voltage. When the voltage gets to 14.5 vdc or so remove the charger. Never leave a charger or battery tender on an Odyssey battery as most do more harm than good.

With the battery charged, remove the charger and let the terminal voltage stabilize (master still OFF). You should have 12.5vdc terminal voltage for a fully charged battery.

If all is well, try engaging the starter with the panel OFF, but keep your voltmeter on the battery terminals. I suspect you will see the voltage drop below 11 - which, depending on your wiring selection, will be about normal.

If all this checks out, the last step is to modify your engine start procedures so you start with the panel OFF.

Carl
 
Actually, OCV (open circuit voltage) for a fully charged Odyssey should be around 12.8 Volts. Less than that and it is propbably bad.
Vic
 
Warm solenoid question...

The solenoid consumes about 3 amps when it is on. This is about 36 watts.

Think about touching a 25 watt incandescent bulb when it is on...:)

Warm is normal.
 
I guess the question is is it normal to have the Efis G3x touch, go blank when engaging the starter. I have a TCW backup battery that would prevent this but its was not connected.
 
az_gila said:
Warm solenoid question...

The solenoid consumes about 3 amps when it is on. This is about 36 watts.

Think about touching a 25 watt incandescent bulb when it is on...:)

Warm is normal.
Click to expand...

Yep - it turns out the master solenoid is a power hog. I had two of these (one for each battery) so they were consuming more power than anything else.

I now use these: https://www.amazon.com/SYSTEMS-Blue...=1471711697&sr=8-4&keywords=blue+sea+solenoid

It draws only 0.13 amps for hold current. The price is too high - but I was able to find them for a lot less on eBay.

Carl
 
laz said:
I guess the question is is it normal to have the Efis G3x touch, go blank when engaging the starter. I have a TCW backup battery that would prevent this but its was not connected.
Click to expand...

Very few instruments will operate at a voltage low enough for the starter to engage and them stay on. It is normal for the EFIS to reset when you crank. That is one of the benefits of the TCW backup battery.
 
I thought you were supposed to have your radios and electronics powered off when starting. Is that idea out of date?
 
tthrew said:
I thought you were supposed to have your radios and electronics powered off when starting. Is that idea out of date?
Click to expand...

Most instruments are best to leave off during start unless you have a backup power source. The EFIS that shows engine data, however, should be on, so you can verify oil pressure immediately after start. The Dynon's have built in (or built into the main harness) dedicated backup batteries. The AFS prior to the 5000 series have built in batteries. The AFS 5000 series and the G3X have a backup power inout that can be run off a separate battery that is not used to crank the engine (the TCW battery is built for this).
 
The Lamar continuous duty contactor draws about 800ma (0.8a), not all that much.

Pull in and drop out voltages are rated at 8/4.5v respectively, curious what those are for the blue sea.
 
Carl Froehlich said:
Yep - it turns out the master solenoid is a power hog. I had two of these (one for each battery) so they were consuming more power than anything else.

I now use these: https://www.amazon.com/SYSTEMS-Blue...=1471711697&sr=8-4&keywords=blue+sea+solenoid

It draws only 0.13 amps for hold current. The price is too high - but I was able to find them for a lot less on eBay.

Carl
Click to expand...

Where DID i put that old copper knife switch????? :)

I remember seeing this contactor noted somewhere in Aeroelectric docs. Very nice, but pricey as you said. Still thought about it. Mine is a B&C S701-1. My load chart shows 1 amp for it.
 
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