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or Start and no shutdown TATTLETALE
®
circuit is latched on.
This can be used to signal that the generator engine is ready to
start or is running.
3-3 MC-900-2.
3-3.1 Control / Display Module. The Control / Display
Module, figure 3-2.1, is also used as on the Model MC-900-2.
3-3.2 Relay Module. The Relay Module, figure 3-3.2,
includes all of the control and shutdown relays that are
required to make up the generator engine control. Relays are
available for operation on either 12 or 24 volt battery systems.
Three (3) relays are included for:
3-3.2.1 Fuel Relay; this relay provides two outputs, one to
energize the engine fuel solenoid and a separate circuit to
energize the battery charging alternator field.
3-3.2.2 Shutdown Relay; this relay is operated by the
shutdown circuits of the Control / Display Module and
provides an output that can be used to trip the generator circuit
breaker on an emergency shutdown.
3-3.2.3 Overspeed Relay; operates only on an Overspeed
shutdown. This relay provides an output to trip an air shut off
solenoid to close the air damper on a two cycle engine.
3-2.3 Status Signal; The relay module also includes an output
that can be used with external circuits for signaling or control
functions.
3-2.3.1 The Run signal at terminal 17 is on (closed to
negative) as long as the Mode Selector Switch is in either Run
or Start and no shutdown TATTLETALE
®
circuit is latched on.
This can be used to signal that the generator engine is ready to
start or is running.
Section 4: Installation
4-1 Location.
4-1.1 The MC-900 series is designed to mount in a
MURPHYMATIC
®
Generator Control panel with the Control /
Display module on the front panel and the Relay module on
the inside bottom surface. Other types of installation is
possible as long as the relationship of the two modules are
maintained.
4-1.2 Clearance for Installation and Service; The modules
must be accessible for wiring to the terminal blocks and
adjustment of the user controls on the back of the Control /
Display module. Figure 4-1.2 shows the mounting dimensions
and the minimum clearances recommended for installation.
4-1.3 Wiring Terminals; Terminal blocks are provided on
both sides of the Control / Display enclosure and the Relay
Module. Torque all terminal screws to 12 inch pound
maximum.
4-2 Wiring.
4-2.1 After the MC-900 has been located and installed, the
wiring connections can be made. This work should be done
with all electrical power disconnected from the engine. BE
SURE THAT THE BATTERY IS DISCONNECTED.
4-2.2 All electrical installation work should be done in
accordance with the National Electrical Code, NFPA-70, and
all applicable local codes.
4-2.3 In general, the following connections will be made:
(a) Battery positive and negative.
(b) Engine run device, such as a fuel shutoff solenoid.
(c) Engine speed sensor, such as a magnetic pickup or the
tachometer output of a battery charging alternator.
(d) Engine starter circuit; an auxiliary starter solenoid is
required to handle most starter solenoid requirements.
(e) Shutdown sensing switches as required.
4-2.3.1 The complete wiring of a Model MC-900 control is
shown in figure 4-2.3.1. Provision is made in the MC-900
series to operate remote lights for all of the shutdown circuits
however these circuits do not have to be wired for the MC-900
to function.
4-2.3.2 Figure 4-2.3.2 is for wiring of the MC-900-2 control.
The same provisions as for the MC-900 are made.
4-2.3.3 Wire Termination; the terminal blocks that are
supplied requires that all wires be terminated with #6 stud size
forked spade solderless wire connectors or stripped and
inserted under the captive terminal plates. Torque all terminal
screws to 12 inch pound maximum.
4-2.3.4 All inductive loads (relays-soleniods-coils-etc.) that
are connected to the MC-900 must have reverse diodes wired
3
DC12V
3AMP Fuse
1
4
5
6
7
8
9
10
11
15
4
16
17
18
19
20
21
22
23
24
25
RH2V2
-U
6-1/4 in.
(159 mm)
4-1/2 in.
(114 mm)
J1
TB2
Torque
Terminal
12 lbs
Torque
Terminal
12 lbs
12
13
14
DC12V
RH2V2
-U
For continued protection against
fire & shock hazard, replace only
with same type fuse & rating.
WARNING
J2
DC12V
RH2V2
-U
TB1
Figure 3-3.2
DC12V
3AMP Fuse
1
4
5
6
7
8
9
10
11
15
4
16
17
18
19
20
21
22
23
24
25
RH2V2
-U
6-1/4 in.
(159 mm)
4-1/2 in.
(114 mm)
J1
TB2
Torque
Terminal
12 lbs
Torque
Terminal
12 lbs
12
13
14
DC12V
RH2V2
-U
For continued protection against
fire & shock hazard, replace only
with same type fuse & rating.
WARNING
J2
TB1
Figure 3-2.2