CSP-HMI-3MD Helicopters, Inc.
MAINTENANCE MANUAL
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[ Chapter 95 TOC ]
95-00-00
Page 807
Revision 7
The information disclosed herein is proprietary to MD Helicopters, Inc.
Neither this document nor any part hereof may be reproduced or transferred to
other documents or used or disclosed to others for manufacturing or any other
purpose except as specifically authorized in writing by MD Helicopters, Inc.
Copyright © 1999−2016 by MD Helicopters, Inc.
(8). Check wiring modification for discre
pancies.
(9). Reinstall circuit breaker panel.
(10). Reconnect electrical wiring harness
connector to EPO warning control unit
plug P19.
(11). Reinstall instrument panel fairings and
hood.
(12). Make wiring changes in applicable
wiring diagrams (Ref. Chap. 96).
(13). Turn on electrical power and check
utilty light and main rotor transmission
warning lights functions with EPO
circuit breaker tripped.
(14). Record wiring modification in Com
pliance Record of helicopter Log Book.
A. Weight and Balance Data
Helicopter weight and balance are not affected
by this modification.
5. T.O.T. Resistor Board Assembly (TB9)
Modification
This modification provides instructions for
rework of the 369H4237-7 and -21 resistor
board assembly (TB9). These instructions
cover the necessary procedures to add a
resistor which enables operators finer tuning
capability of the TOT indicating system and if
required, to remove a section of the resistor
board allowing compatibility with existing
TOT indicators.
Consumable Materials
(Ref. Section 91−00−00)
Item Nomenclature
CM217 Isopropyl alcohol
CM815 Solder
Special Tools
(Ref. Section 91−00−00)
Item Nomenclature
ST1010 Volt-ohmmeter
ST1011 Turbine temperature indicating system
test set
(1). Set BATT-OFF-EXT PWR switch to
OFF position.
(a). Tag and disconnect wires from TOT
resistor board.
(b). Remove resistor board from TOT
indicator.
(2). Modify resistor board as follows (Ref.
Figure 806):
Circuit board is fragile, careful
ly remove marked area with
dremel tool and cutting disk or equivalent to
avoid cracking (Ref. Figure 806).
(a). Remove material indicated by cross
section area on resistor board assem
bly (optional).
(b). Drill 0.038-0.045-inch
(0.9652-1.143 mm) holes for resistor
wire leads. Use 1/32 inch (0.79375
mm) drill bit.
NOTE: Variable resistor (3057Y-1-100) has
three wire leads and requires adjustment
prior to installation. Fixed resistor
(RN55D10R0F) has two wire leads.
(c). Using meter (ST1010), adjust each
variable resistor to read 8.0 ±0.05
ohms prior to soldering.
(d). Insert resistor wire leads through
board. Trim and bend wire leads flat.
Attach leads using solder (CM815).
(e). Clean solder joints with alcohol
(CM217).
(f). Drill 0.125-0.130-inch (3.175-3.302
mm) rivet hole. Use 1/8 inch (3.175
mm) drill bit.
(g). Install terminal lug, washer and
rivet.
(h). Install resistor board to TOT indica
tor. Attach wires to resistor board
terminal lugs, remove tags.
NOTE: For dual variable resistor
(3057Y-1-100) installation, alternate ad
justment between each resistor to equalize
resistance.
(i). Perform T.O.T. Indicating System
Calibration (Ref. Sec. 95-30-00).
CAUTION
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