Murphy MC-900 Series manual Installation, Location, MC-900-2, Wiring

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Terminal

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WARNING

For continued protection against fire & shock hazard, replace only with same type fuse & rating.

3AMP Fuse

RH2V2	RH2V2
-U	-U

DC12V DC12V

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6-1/4 in.

(159 mm)

shutdown. This relay provides an output to trip an air shut off solenoid to close the air damper on a two cycle engine.

3-2.3Status Signal; The relay module also includes an output that can be used with external circuits for signaling or control functions.

3-2.3.1The 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.

4-1.1The 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

4-1/2 in.

(114 mm)

Figure 3-2.2

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.

3-3.1Control / Display Module. The Control / Display Module, figure 3-2.1, is also used as on the Model MC-900-2.

3-3.2Relay 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.

the inside bottom surface. Other types of installation is possible as long as the relationship of the two modules are maintained.

4-1.2Clearance 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.

4-1.3Wiring 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.

TB1

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7

8

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11

12

13

14

Torque

Terminal

12 lbs

J1J2

WARNING

For continued protection against fire & shock hazard, replace only with same type fuse & rating.

3AMP Fuse

RH2V2	RH2V2
-U	-U

DC12V DC12V

RH2V2

-U

DC12V

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4

16

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24

25

Torque

Terminal

12 lbs

6-1/4 in.

(159 mm)

4-2.1After 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.

4-2.2All electrical installation work should be done in accordance with the National Electrical Code, NFPA-70, and all applicable local codes.

4-2.3In 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.

4-1/2 in.

(114 mm)

Figure 3-3.2

Three (3) relays are included for:

3-3.2.1Fuel Relay; this relay provides two outputs, one to energize the engine fuel solenoid and a separate circuit to energize the battery charging alternator field.

3-3.2.2Shutdown 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.

3-3.2.3Overspeed Relay; operates only on an Overspeed

4-2.3.1The 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.

4-2.3.2Figure 4-2.3.2 is for wiring of the MC-900-2 control. The same provisions as for the MC-900 are made.

4-2.3.3Wire 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.

4-2.3.4All inductive loads (relays-soleniods-coils-etc.) that are connected to the MC-900 must have reverse diodes wired

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