local audible (K-4) terminal 20 and 21, remote audible (K-5)
terminal 22 and 23 and remote visual (K- 6) terminal 24 and 25
close to operate the alarm devices wired to them.
7-3.3 An alarm silence pushbutton is wired between terminal 35
and ground. This switch is provided on the A901 and can be
externally connected on the A902 series. When this switch is
closed, the audible alarm relays K-4 and K-5 will drop out if they
are closed. This turns off the audible alarms but does not affect the
individual alarm lights on the panel. The lights will remain on
until the input switches open. If no alarm silence switch is
provided, the alarm relays will reset when the alarm and / or
shutdown lights reset.
Section 8: Service Parts
8-1 Table 8-1 covers all of the replaceable components of the
A900 Series Generator Engine Controls. The part numbers that are
shown are Frank W. Murphy Mfr. numbers, and may not appear on
the individual parts.
8-1.1 Each complete control is made up of a Control/Display
Module, a Relay Module and a number of Relays.
8-1.2 There are no field replacement parts in the Control/Display
Module. The complete module must be replaced if it fails. All
relays are individually replaceable in the Relay Module but the
module must be replaced if a failure of the circuit board occurs.
8-2 Table 8-2 displays replaceable components for the A900 series
controls manufactured for Detroit Diesel Corporation.
These components have Murphy part numbers. In addition, they
are OEM parts and are available only to Detroit Diesel and their
distributors.
8-2.1 The A900-DDC parts are the same as the Murphy A900
series that has been covered throughout the A900 manual except
the “Spare Shutdown” circuit is labeled “Low Water Level” and
the DDC logo is printed on the face plate.
Table 8-1: Replacement Components for A900 Series Generator Engine Controls
Model Number
Part Number
Control/Display Module
Relay Module
Relay Part Number
Relay Qty
A901-12
40-02-0132
40-00-0077
40-00-0064
00-00-2952
5
A901-24
40-02-0137
40-00-0077
40-00-0064
00-00-2953
5
A901-2-12
40-02-0134
40-00-0078
40-00-0064
00-00-2952
6
A901-2-24
40-02-0140
40-00-0078
40-00-0064
00-00-2953
6
A902-12
40-02-0133
40-00-0079
40-00-0064
00-00-2952
3
A902-24
40-02-0145
40-00-0079
40-00-0064
00-00-2953
3
A902-2-12
40-02-0135
40-00-0080
40-00-0064
00-00-2952
4
A902-2-24
40-02-0148
40-00-0080
40-00-0064
00-00-2953
4
A903-12
40-02-0151
40-00-0081
40-00-0064
00-00-2952
3
A903-24
40-02-0152
40-00-0081
40-00-0064
00-00-2953
3
A903-2-12
40-02-0155
40-00-0082
40-00-0064
00-00-2952
4
A903-2-24
40-02-0156
40-00-0082
40-00-0064
00-00-2953
4
Table 8-2: Replacement Components for A900 Series Controls for Detroit Diesel Corporation
Model Number
Part Number
Control/Display Module
Relay Module
Relay Part Number
Relay Qty
A901-12-DDC
40-35-0020
40-00-0083
40-00-0064
00-00-2952
5
A901-2-24-DDC
40-35-0029
40-00-0084
40-00-0064
00-00-2953
6
A902-12-DDC
40-35-0022
40-00-0085
40-00-0064
00-00-2952
3
A902-2-24-DDC
40-35-0037
40-00-0086
40-00-0064
00-00-2953
4
A903-12-DDC
40-35-0024
40-00-0087
40-00-0064
00-00-2952
3
A903-2-24-DDC
40-35-0043
40-00-0088
40-00-0064
00-00-2953
4
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