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Section 4 • Operation
VSS/VSM/VSH/VSSH • Installation, Operation and Maintenance Manual • Emerson • 35391SD
Compressor
Model
Command Shaft Rotation No. of Turns/Rotation Angle/Slide Travel
Capacity Volume Capacity Volume
INC DEC INC DEC Turns Degrees Travel Turns Degrees Travel
VSM 71
VSM 91
VSM 101
VSM 151
VSM 181
VSM 201
VSM 301
VSM 361
VSM 401
CW CCW CW CCW 0.80 288 3.141” 0.45 162 1.767”
VSM 501
VSM 601
VSM 701
CCW CW CCW CW 0.91 328 3.568” 0.52 187 2.045”
VSS 451
VSS 601
CW CCW CW CCW 0.91 328 3.568” 0.52 187 2.045”
VSS 751
VSS 901
CCW CW CCW CW 1.09 392 4.283” 0.63 227 2.473”
VSS 1051
VSS 1201
VSS 1301
CCW CW CCW CW 1.22 439 4.777” 0.74 266 2.889”
VSSC 1501 CCW CW CCW CW 1.36 490 5.325” 0.82 295 3.200”
VSS 1551 CCW CW CCW CW 1.48 533 5.823” 0.87 313 3.433”
VSS 1801 CCW CW CCW CW 1.36 490 5.325” 0.82 295 3.200”
VSS 1851
VSS 2101
CCW CW CCW CW 1.48 533 5.823” 0.87 313 3.433”
VSS 2401
VSS 2601
VSS 2801
VSS 3001
CCW CW CCW CW 1.80 648 7.072” 1.36 490 5.341”
Table 4-1. Command Shaft Rotation Specications*
*The large gear on the command shaft has 50 teeth. The teeth are counted when moving the command shaft from the
minimum stop position to the maximum stop position.
The manual operating shaft on the gear motor should be turned the opposite direction of the desired command shaft
rotation.
The capacity and volume control motors are equipped with a brake, if it is necessary to operate the control motors manu-
ally, the brake must be disengaged. The brake can be disengaged by pushing on the motor shaft on the cone end. The shaft
should be centered in its travel. Do not use excessive force manually operating the motor or damage may result.