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EIS4000 Power Switch

petehowell

petehowell

Well Known Member
Hello,

Have most builders installed a power switch for the EIS4000 or have they just set it up on the main bus to come on with the master?


Thanks,

Pete
 
On with the Master

Mine comes up any time the Master is on - it's all the engine instrumentaiton I have, so I figure I want to see it right away....I can always kill it at the breakers.

Paul
 
I put it on a switch. I like the idea of having everything individually switchable. My ADI didn't have a switch, so I gave it one too. I just like the idea of being able to turn something off if I need to.

Steve Zicree
RV4 finishing
 
Last edited:
Ok

Greg says it is OK to be on during engine cranking, and you needed it for engine info on start-up. On with master. G
 
By far and away the large majority of EIS users I've experienced put at least that box (EIS) on the main bus to come on with the master. That way it's on during engine start and you'll know if you have oil pressure or not! That's the way we do it. A separate switch is fine if you like, but certainly not needed, nor do you absolutely need to have a switch for everything on your panel. Just kludges things up an adds more wire and complexity where it's not needed.....plus it's one more thing to troubleshoot when the gremlins move in :)

We normally wire them to the main bus, but make sure they have their own breaker or fuse as is good practice.

Cheers,
Stein.
 
I can definitely see it from Stein's point of view, but gremlins are precisely the reason I wanted the two extra switches (ADI and EIS). I admit to having no idea how either of these devices work, but I figure if they ever start doing anything weird they will be best protected from further harm by powering them down. I also have a very simple day VFR plane and thought that if I ever needed to conserve battery time, I could shut these non-essential items down (No, I didn't bother with an essential buss).

Steve Zicree
RV4 wing roots tomorrow
 
i have a seperate switch for mine. I have yet to forget to turn it on prior to engine start (although its only a matter of time).
 
szicree said:
I can definitely see it from Stein's point of view, but gremlins are precisely the reason I wanted the two extra switches (ADI and EIS). I admit to having no idea how either of these devices work, but I figure if they ever start doing anything weird they will be best protected from further harm by powering them down. I also have a very simple day VFR plane and thought that if I ever needed to conserve battery time, I could shut these non-essential items down (No, I didn't bother with an essential buss).

Steve Zicree
RV4 wing roots tomorrow
Click to expand...

Its a valid point, but an EIS draws less than an amp so you won't gain very much by shutting it down and you lose your volt meter, and possibly ammeter. Mine comes on with the master.

Pete
 
penguin said:
Its a valid point, but an EIS draws less than an amp so you won't gain very much by shutting it down and you lose your volt meter, and possibly ammeter. Mine comes on with the master.

Pete
Click to expand...

I agree it's not much, but if my electrical is running on electron fumes and I get to choose between EIS and a working com, I'll take the latter. Also, the current draw of less than 1 amp is when the thing is working correctly. If it goes on the fritz could it draw more? The manual says to fuse it with a 5 amp, which suggests maybe it could. All this aside, I just went with the install manual, which had a switch.

Steve Zicree
 
Steve,

I'm not disagreeing with you, but ...

One advantage of the EIS is that the BRL (Big Red Light) flashes at you when any parameter is exceeded - for example buss voltage falls below 13.0v (or what ever you set the value to). So its unlikely that you will be running on electron fumes. The most likely failure mode (that leaves the battery able to provide power) is an alternator failure - for what ever reason. When the battery starts powering the system you will find out straight away - and you can make appropriate decisions to avoid the "electon fume" scenario. For example, with a reasonable charge in the battery, and sensible load shedding (strobes, etc), you will probably have more electrons in the battery than gas in the tanks!

By all means put a switch in the line, just giving you something to think about.

Pete
 
Steve, I am disagreeing with you ;)

I find it odd that you worry about the (highly unlikely) scenario of running on electron fumes, and yet you said in a prior post that you didn't both with an E-bus setup. The battery contactor draws more power than the EIS. If you want to be able to shed load down to bare minimum, then the E-bus is the only way to do it.

Also, the fuse size has little to nothing to do with the current draw of the unit. The fuse is there to protect the wire, not the box.
 
I seriously considered the E-bus, but opted out of it for my plane. I've got vfr instrumentation, single com, 196 handheld, ADI, EIS, P-mags, no lights, no efis. When I started planning what to put on the e-bus it was going to be pretty much everything but the contactor. On a plane that runs fine without juice, I just couldn't see the point. Regarding switching the EIS, it just seemed like a real easy thing to do, it complied with manufacturer's instructions, and it does allow me the option of taking it off line for any reason, however unlikely. Regarding fuses, I'm aware that they are there only to protect the wiring, but I'm saying that the manual advises using a 5 amp, which won't blow until a whole lot of juice has gone down the drain. Are there any known failure modes of the EIS or it's sensors that result in an abnormally high current drain? I sure don't know, but I just like the idea of being able to turn stuff off if it starts to go crazy.

Steve Zicree
 
Switch it

I'm with you Steve. It is nice to have the option to turn off each "in-cockpit smoke generator" individually.
Do what will make you happy, since you are the one who will be flying the airplane.
 
That is why pullable CB's are good

redbeardmark said:
I'm with you Steve. It is nice to have the option to turn off each "in-cockpit smoke generator" individually.
Do what will make you happy, since you are the one who will be flying the airplane.
Click to expand...
That is why it is on it's own pull-able Circuit Breaker, as all my Main Buss circuits are. George
 
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