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Murphy HD9063 Series Installation And Operation Instructions page 2

Murphy dual set point speed switch installation and operation instructions

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Mounting
1. Drill four 3/16 in. (5 mm) diameter mounting holes (refer to
mounting hole dimensions above).
2. Align the plastic standoffs on the HD9063 with the 4 mounting
holes and push gently until standoffs snap into place.
CAUTION: Pushing too hard could damage board.
Crank Disconnect Relay
An understanding of the crank disconnect function for your par-
ticular system is critical to speed switch installation. It is also
important to consider the 5 A current limitation of K1 relay con-
tacts. Figure 1 illustrates the use of a low-current pilot relay to
operate the high-current starter solenoid. In operation, battery
voltage is supplied through the normally closed contacts of the
speed switch crank disconnect relay K1. When the engine starts,
K1 energizes and its normally closed contacts open. This action
de-energizes the pilot relay and inhibits the starter from operating
until the engine nearly stops. The normally open contacts may be
used if a contact closure is required to disable the cranking func-
tion for your system.
Crank
Disconnect Relay
K1
1
2
Crank
Enable
Battery
Figure 1
MOUNTING DIMENSIONS
HD9063 and HD9063-USOS
4 in. (102 mm)
Mounting Holes
CRANK
DISCONNECT
2-1/4 in.
(57 mm)
NC
Mounting
INTERNAL
CRANK
NO
DISCONNECT
Holes
RELAY
C
CONTACTS
1 2 3 4 5 6 7 8 9 10 11 12
Mounting
Standoffs
4 Places
RELAY FUNCTIONS
Battery
3
Starter
Pilot Relay
To
Starter Solenoid
OVERSPEED
EXT.
MAG.
PICKUP
EXT.
NC
TEST
INTERNAL
NO
OVERSPEED
EXT.
RELAY
C
POWER
CONTACTS
(+)
( )
(+)
( )
4-1/2 in.
(114 mm)
Mounting
1. Drill four 1/4 in. (6 mm) diameter mounting holes (refer to mount-
ing hole dimensions above).
2. Secure with four 10-32 screws.
Overspeed and Underspeed Relay
NOTE: Underspeed relay available on HD9063-USOS only.
The overspeed and underspeed functions of the speed switch may
be used in various systems to effect engine shutdown or actuate an
alarm in the event of engine overspeed or underspeed. Figure 2
illustrates the overspeed/underspeed function being used to control
a fuel rack solenoid. In this application, battery voltage is available
to the solenoid through normally open contacts of the relay (K2
overspeed) (K1 underspeed). If the engine speed exceeds the nor-
mal overspeed or underspeed set point, relay K1 or K2 energizes
and this voltage energizes the solenoid, shutting down the engine.
Similarly, the normally closed contacts may be used if engine shut-
down is to be initiated by removal of battery voltage.
Underspeed Relay K1
NO
NC
1
2
3
Battery
Off
Start
Starter
Switch
HD-96044N page 2 of 4
2-3/4 in.
(70 mm)
3/4 in.
(19 mm)
Overspeed Relay K2
NO
NC
Contact opens on overspeed or
underspeed and drops out solenoid.
1
2
3
Energize
NO
Starter Contactor
Relay
Figure 2
OPTIONAL
Hold
Energize
Starter

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