TSE DPT40-B, Owner'S Manual

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41
Series 90 Inspections and Adjustments 8
The NSS must be adjusted to meet the following
three requirements:
i. The distance the control handle can be turned
without opening the NSS is called the “NSS
deadband.” The distance the control handle can
be moved without moving the control spool enough
to port hydraulic fluid to the pump displacement
control cylinders is called the “control deadband.”
These deadbands must be centered in relation to
each other.
Since the position of the control deadband cannot
be adjusted, the position of the NSS deadband
must be adjusted to match it. The switch pin is
located in an eccentric plug which is turned to
move the center of the NSS deadband.
ii. The NSS deadband must be wide enough so the
NSS will not open within the loose area of control
handle movement caused by normal operating
clearances in the control linkage (control shaft
“free-play”). By setting the NSS to open outside
this area, the control spool springs or control shaft
centering spring can always act to return the
handle to “neutral” and re-close the NSS.
iii. The NSS deadband must be narrow enough so
the NSS will open before the unit builds 7 bar (100
psi) differential system pressure in either direc-
tion.
The neutral start switch is threaded into the spe-
cial lock nut for the eccentric plug. Turning the
NSS clockwise (CW) into the special nut will move
the NSS closer to the switch cam on the control
shaft, and will narrow the NSS deadband. Turning
the NSS counterclockwise (CCW) out of the spe-
cial nut will move the NSS farther from the switch
cam on the control shaft, and will widen the NSS
deadband.
(continued)
Control Shaft
"Free-Play"
Control Shaft
Total Control
Shaft Rotation
Control Deadband
("Neutral")
NSS Deadband
(Switch Closed, "ON")
Neutral Start Switch Adjustment Requirements
90000831
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