Service Kit Instructions
Series 42
Manual displacement control neutral start switch
The Neutral Start Switch (NSS) prevents the engine from beingstartedwhenthepumpcontrolhandleisoutofneutral. The NSS should be wired in series with the engine starting circuit. The switch contact is closed at the handle’s neutral position and opens when the control handle is rotated 1.5° to 2° from neutral.
The Backup Alarm Switch (BUA) outputs an electronic signal when the control handle is in a reverse position. This switch is normally wired in series with an audio output. The switchcontactisopenuntilthecontrolhandleisrotated2.6° to 3.75° in the reverse direction.
WARNING:
The control handle’s neutral position must agree with the pump’s neutral position for the NSS/BUA to work e ectively.
NSS Cover
NSS Control Nut
NSS Cam
Alignment
Plug
NSS Cavity
NSS with
Weatherpack
NSS with Screw
Terminals
The Neutral Start/Backup Alarm Switch assembly can be configured for three di erent setting.
i.A Neutral Start Switch only.
ii.A Neutral Start Switch with Backup Alarm for units where clockwise (CW) handle rotation results in “reverse” motion.
iii.A Neutral Start Switch with Backup Alarm for units where counterclockwise (CCW) handle rotation results in “reverse” motion
The setting must be in accordance with the configuration of the unit. See the model code if uncertain of the type of NSS you have.
NSS Assembly on MDC
Control
Yolk Cam
NSS only |
NSS with BUA |
NSS with BUA |
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(CW = Reverse) |
(CCW = Reverse) |
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ii. |
iii. |
Top View of NSS Showing Cam Positions
© Danfoss, 2013 |
BLN-10123 • Rev AA • September 2013 |
1 |
Note: Adjustmentisnormallyrequiredunlessthefunction of the NSS is changed (between i, ii, and iii).
Adjustment of the NSS or NSS and BUA requires a special alignment tool. Dimension are give at right.
Adjustmentisperformedbysettingthecampositionswithin the NSS assembly
1. |
The Manual Displacement Control (MDC) must be |
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removed from the housing. |
2. |
Remove the NSS ( 7/8 inch hex). |
3.Remove and discard the NSS cover by inserting a screwdriver into the NSS cavity and popping o the cover with a hammer. Be careful not to damage the internal hardware.
4.Remove the control nut (8 mm hex).
5.Use a screwdriver to pop o the cam.
6.On the underside of the MDC, gently clamp a pair of locking pliers around the spring contacts of the control cam. Be careful not to dambe the spring wires. The pliers should hold the nub on the control cam to the pin underneath. This will hold the control cam in neutral position.
7.Set cam in proper orientation according to the unit’s configuration.
8.Screw special alignment tool in NSS cavity to hold cam in place.
9.Place control nut on cam and torque to 4.1 to 6.8 Nm (3 - 5 ft•lbf).
10.Press new cover on top of cam cavity. This requires either an arbor press or a full-sized punch. The tool diameter should be 23.3 mm (0.916 in). Press the new cover so that it sits 1.06 mm (0.0417 in) below the cast surface as illustrated at right.
11.Remove the alignment tool and locking pliers.
12.Place a new lubricated O-ring on NSS.
13.Reconnect the NSS to the MDC. Torque to 25 - 29 Nm (18 - 22 ft•lbf).
14.Reinstall MDC onto pump housing.
9/16 -18UNF 2A THD
.04 x 45 Chamfer
R.125 |
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ø .236 –.030 |
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Knurl |
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35.0
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1.250 |
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.306 |
.354 |
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2.000 |
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Material: .75 DIA x 3 ETD150 |
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(All Dimensions in inches) |
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Alignment Tool |
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23.3 mm |
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NSS Cover |
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(0.916 in.) |
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1.06 mm |
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NSS Control Nut |
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(0.0417 in.) |
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NSS Cam |
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NSS
Side View of NSS and NSS Cavity
Underside of MDC Showing Clamping Position
of Locking Pliers
© Danfoss, 2013 |
BLN-10123 • Rev AA • September 2013 |
2 |