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-   -   Warm Master Selenoid (https://vansairforce.net/community/showthread.php?t=141045)

laz 08-20-2016 08:36 AM

Warm Master Selenoid
 
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

Ron B. 08-20-2016 08:43 AM

(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.

Carl Froehlich 08-20-2016 08:57 AM

Quote:

Originally Posted by laz (Post 1104946)

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

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

vic syracuse 08-20-2016 10:23 AM

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

az_gila 08-20-2016 10:32 AM

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.

laz 08-20-2016 10:51 AM

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.

Carl Froehlich 08-20-2016 10:54 AM

Quote:

Originally Posted by az_gila (Post 1104985)
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.

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-...e+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

Jesse 08-20-2016 10:56 AM

Quote:

Originally Posted by laz (Post 1104991)
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.

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.

tthrew 08-20-2016 06:47 PM

I thought you were supposed to have your radios and electronics powered off when starting. Is that idea out of date?

az_gila 08-20-2016 06:51 PM

Quote:

Originally Posted by tthrew (Post 1105087)
I thought you were supposed to have your radios and electronics powered off when starting. Is that idea out of date?

It is if the parts are from Dynon...:)

Jesse 08-20-2016 07:02 PM

Quote:

Originally Posted by tthrew (Post 1105087)
I thought you were supposed to have your radios and electronics powered off when starting. Is that idea out of date?

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).

Walt 08-20-2016 07:04 PM

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.

rzbill 08-21-2016 05:59 AM

Quote:

Originally Posted by Carl Froehlich (Post 1104992)
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-...e+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

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.

Walt 08-21-2016 06:20 AM

Quote:

Originally Posted by rzbill (Post 1105132)
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.

The Eaton unit is the one you are thinking of:
http://www.skygeek.com/eaton-aerospa...omagnetic.html

rzbill 08-21-2016 06:40 AM

Quote:

Originally Posted by Walt (Post 1105136)
The Eaton unit is the one you are thinking of:
http://www.skygeek.com/eaton-aerospa...omagnetic.html

You made me look..:)

My memory was off. I was thinking of a CII Technologies EV-200 contactor that Bob N was suggesting for a starter contactor. Very similar form factor to the Blue Sea but different application so the coil will be different.

wm708 08-21-2016 04:39 PM

Thinking about using this solenoid. No power used while activated.
What you say?

http://www.partdeal.com/cole-hersee-...3ZEaAhWR8P8HAQ

Bill

Carl Froehlich 08-21-2016 06:11 PM

Quote:

Originally Posted by wm708 (Post 1105281)
Thinking about using this solenoid. No power used while activated.
What you say?

http://www.partdeal.com/cole-hersee-...3ZEaAhWR8P8HAQ

Bill

Latching solenoids tend to not be suitable for aircraft use. While it might stay latched with power removed, it could open on a minor G bounce. Without any specs you cannot tell.

Carl


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