TSE DPT40-B, Owner'S Manual

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Series 90 Inspections and Adjustments 8
NSS Deadband Adjustment (Conditions ii & iii)
The NSS deadband must be wide enough so the NSS
will not open within the control shaft “free-play” area,
and it must be narrow enough so the NSS will open
before the unit builds 7 bar (100 psi) differential
system pressure in either direction.
1. Using two 1-1/8 inch wrenches, hold the neutral
start switch from turning and loosen the locknut.
2. Disconnect the external control linkage and make
certain the control shaft is in its “neutral” position.
3. Attach a continuity checker to the terminals of the
switch. With the control shaft in its “neutral” posi-
tion, turn the switch clockwise (CW) until electrical
continuity is broken, then turn the switch counter-
clockwise (CCW) until electrical continuity is ob-
tained. Turn the switch counterclockwise (CCW)
an additional 1/4 turn (90
°
) after continuity has
been obtained.
4. Hold the switch in place and tighten the locknut to
27 Nm (20 ft•lbf) torque.
5. With the continuity checker attached to the switch,
rotate the control handle (or the control shaft) in
each direction to assure continuity is broken when
the control is not in the “neutral” position.
6. If continuity is obtained in “neutral” and satisfacto-
rily interrupted in each direction, proceed to check
the switch with the prime mover running. The
switch must open before the unit builds 7 bar (100
psi) differential system pressure in either direc-
tion.
If the switch opens after the unit builds system
pressure in either direction, loosen the switch lock
nut and turn the switch clockwise (CW) 1⁄12 turn
(30
°
). Tighten the switch lock nut and recheck the
switch operation. Repeat this procedure if neces-
sary.
7. If neutral start switch operation is satisfactory,
reconnect the external control linkage.
8. If continuity is not interrupted with an equal move-
ment of the control handle in each direction,
continue with the next section.
Checking Continuity of NSS
NSS Details
Eccentric Plug
Switch Pin
Special Lock Nut
for Eccentric Plug
1-1/8 in. hex wrench
Torque: 27 Nm (20 lbf•ft)
Switch Cam
Control Shaft
Neutral Start Switch
Switch Lock Nut
Loosening the NSS Lock Nut
90000253
90000255
90000832
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