Tracy,
Thanks for the clarification.  I plan on making my own CHT thermocouples by tig welding one end of J-type thermocouple wire and inserting into a 1/8" hole in the rotor housing.  What method would you suggest to keep the sensing end from shorting once inserted into the rotor housing?  Would 1/16" shrink tubing work?

Mark S. 


  At 09:57 AM 3/17/2004 -0500, you wrote:

The EM2 will work with either grounded or ungrounded CHT (J type)  and EGT (K type)  thermocouples.  BUT!  They must be one or the other, not "maybe" grounded.  If ungrounded, you need to follow the instructions in the installation guide about grounding the red TC lead at the connector to one of the spare ground terminals.  Then make sure the sensing end does not short to ground.
 
Most CHT & EGT sensors are grounded type (TC welded or clamped to grounded part of the sensor).
 
Tracy Crook
 

----- Original Message -----

From: Mark Steitle

Sent: Tuesday, March 16, 2004 7:02 PM

To: Rotary motors in aircraft

Subject: [FlyRotary] EGT/CHT wiring

 

I've been wrestling the wild EMU and need some help!  (actually, it has

been pretty easy, and fun, in a wierd sort of way).

I purchased the EGT probes with the weld-on bungs from ACS.  The problem is

the leads are only about a foot long and they have ring terminals on the

ends.  Do I cut these and solder (or weld) extensions so they will reach

the EMU box?  Would a standard terminal block work?  Any other solutions?

For the CHT probes, I have drilled a 1/8" hole in the web next to each

leading spark plug.  The bottom of the hole stops at the steel liner of the

center housing.  I have ordered "J" type thermocouple wire and will tig

weld the connections.  My question is... do I need to insulate the junction

to prevent it from making contact with the metal housing, or does that

matter?  Should I pot these into the holes, or just stick them down into

the holes and leave it go at that?

Mark S.

(my turn to wrestle the wild EMU)

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