EMS-220 Wiring!!

[timfwalsh01]

In anticiaption of installing the Skyview - I have already removed, and sold my EFIS and EMS in my flying Velocity.

Since the EMS-220 will be mounted on the inside firewall.......This weekend I will use the old wire harness for the EMS EGT/CHTs and make them shorter.  Engine is on the back

My question - will the EMS probe wire harness be the same for the EMS-220?  I also need to shorten the wires.

Why do I ask?  The EMS D-10 required a power source.  Now it will be placed on the firewall, which is in the back of the plane for me?

Do I need to run a power line from the front of the plane to the back?  If yes, using the same pin?

Make sense?  Tim

 

[dynonsupport]

The same harness is run for the EMS. Exact same pins.

The EMS module gets it's power from the SkyNet bus cable (the 9 pin that runs to it from the screen).

The pin that used to get power on the EMS is now just used to measure voltage. If you don't hook a wire to it, the EMS won't be able to report system voltage warnings to you. It doesn't need to be a "power" cable, as no current ever flows through it.

 

[timfwalsh01]

Dynon,

Now that I am getting ready to hook up the EMS, I am paying more attention.

I understand the previous EMS D-10 does not need to be a power cable.  But, I must hook up the previous "power" wire to measure voltage.

So, what do I hook the wire up to?  Thanks  Tim

 

[dynonsupport]

You can measure two voltages with the EMS-220. Pins 1 and 2 measure these voltages. It's up to you to decide where these point(s) should be. Do you want it at your buss, at the battery, at the back of an EFIS?

There's no one specific answer, they all give you good, but different info. If you want the same point that an EMS-D10 would measure, then you use the same point you would have powered the EMS from (usually the avionics buss)

 

[flickroll]

The same harness is run for the EMS. Exact same pins.

That does not seem quite right.... For the EMS-D120 pins 34-37 are for DSAB.  On the EMS-220, pins 34 & 35 are low voltage RPM, and 36 & 36 are GP TC.  So, for a retrofit with an existing EMS-D120 harness shouldn't the wires from 34-37 be removed from the connector??

 

[dynonsupport]

Given that DSAB is not used in SkyView, there is no harm in leaving those pins installed. But yes, for the cleanest install one might want to remove a few pins from the harness.

 

[schristo]

after i completed my planning i ended up with quite a number of unused pins and i chose to remove all of them anticipating that it would be easier to add back specific wires rather than fishing about for an existing one within a laced bundle.

 

[vlittle]

You can measure two voltages with the EMS-220. Pins 1 and 2 measure these voltages. It's up to you to decide where these point(s) should be. Do you want it at your buss, at the battery, at the back of an EFIS?

There's no one specific answer, they all give you good, but different info. If you want the same point that an EMS-D10 would measure, then you use the same point you would have powered the EMS from (usually the avionics buss)

What is the input resistance of the voltmeter input pins? I'd like to permanently connect on input directly to the battery (unswitched), but I don't want it to discharge over time if there is too much leakage.

Vern

 

[dynonsupport]

The impedance is 66K ohms, which is about 0.2mA on a 12V battery.

On a 20AH battery this should be 11.5 years.