EFD1000 E5 Dual Electronic Flight Instrument (EFI) Install Manual
DOCUMENT # 900-00041-001
PAGE 203-226
REVISION D
© Copyright 2019 Aspen Avionics Inc.
Wires and connectors must be clearly marked per FAR 23.1365(d).
Wires and wiring bundles must be secured in such a way to eliminate risk of mechanical damage and
minimize exposure to heat and fluids per FAR 23.1365(e).
Figure E6: MS25041-4 Dimmable “Catseye”
E5.5 Fabrication of TR1 or TR2 Transformer Isolation box (Century autopilots only)
It is necessary to isolate the Century autopilot inputs from ground with isolation transformers. The
transformers are standard parts. An appropriately rated certificate holder with a quality system can
fabricate a part in accordance with Part 43. The standard parts can be contained in a junction box as
described below. See AC 43.13-1B and -2B for additional information.
a)
Follow practices described in AC 43.13-1B, Chapter 11 section 11-37 page 11-13 for junction
box construction.
b)
The junction box that houses the transformers must be aluminum. Use of a D-sub connector
(DB-15) is suggested with the wires connected per Figure E7 or E7A below.
c)
Select the appropriate TR Junction box:
i.
TR1 - Century 21/31/41/2000/4000, the three (3) transformers are Triad SP-66 (MIL#
TF5S2 1ZZ). Note – The roll only Century 21autopilot only uses two transformers (T1 and
T3).
ii.
TR2 – Century IIB/III/IV, T1 is a SP20 transformer and T2/T3 are SP69 transformers. The
roll only Century IIB autopilot only uses two transformers (T1 and T3). Install 2.2K ohm
and 1.21K ohm resistors from 403-00009-001 bag as shown. Install 0.12uF capacitor
from bag as shown.
d)
Secure transformers in such a way that they cannot become loose and short out. One way is
with a circuit board (bread board) attached with stand offs and the transformers soldered on the
backside using the circuit board traces or jumper wire. The relay should be attached to the
board or lid of the junction box.
e)
Secure all mounting hardware with locking fasteners so that they cannot come loose in the box.
f)
If a box is used to mount the components, permanently label the box with “ASPEN EA100
TRANSFORMERS TR1” (or TR2) as applicable so that it is clearly visible.
g)
Mark the location of the box in the in the ICA number 900-00012-001 on Figures 1, 2 or 3 as
applicable.
2
1
3
MS25041-4
