Collins 618T-2    

 

OK this page is brand new  1 May 2015,  there are two fellows working long and hard to get T2 information,   THIS page will continue to grow,  so you
618T-2 owners with questions,  STAND BY .. more info to appear here within the next few months

One important piece of information,  
The only difference between a 618T-2 and 618T-3 is the HV power supply module. 
The only place in the T-2 radio using the 3 phase is the High Voltage Power supply.

If you swapped modules, the external wiring changes ...!!!

BE CAREFUL,  study the T-2 and T-3 interconnect diagrams, as well as the
Schematic's of the power supply modules ,,  page 21, and 22..

you CANNOT plug a T-3 into a working T-2 system, and Visa  Versa
 
618T-x_Schematic_Diagrams.pdf 

page 21 Fig 818, shows the T-2  3 phase Hi Voltage module,
page 22  shows the T-3  single phase Hi Voltage module.
 

Power requirements as stated in the
Collins sales literature.

This is not totally incorrect, its just totally
confusing !   read below

The confusion is where you measure the voltage.
note the ""line to line"" 

 

The reference above, as to the 618T-2 requiring 208VAC, 3 phase 400 Hz is incorrect . 
The T-2 requires 115VAC 3 Phase, 400Hz power, & 27.5VDC

There is no 208V power native to commercial jet aircraft,
only 115VAC single and 3 phase.  The placard on 618T-2 also
calls out 115V power req.  (you also need 27.5VDC for the RX)

The Collins sales literature references 208V 400CPS 3 phase.  In actuality, and as discussed, you’re feeding the set 115V 400CPS 3 phase from the aircrafts electrical buss, a rotary generator, or an inverter.  The power source isn’t 208V, it’s 115V.  ONLY when you measure across (2) of the phases do you get 208V.  This is confusing to most folks.  115V 400CPS 3 phase dynamotors are more common that you’d think.  Aside from the noise (I’ll call that “character”), the rotary converter is the simplest way to power a T-2.

 

618T-2_interconnect_with_490t1.pdf (very useful for the T2 radio)