LEESON NEMA 4X SCR Control: 174903.00 (Obsolete) - Manual (Page 7)

MODEL SELECTION
6
The Speedmaster will operate a 90 VDC motor in the H.P. range of 1/8 through 1 H.P., and a
180 VDC motor in the range of 1/4 through 2 H.P., using different trimpot settings.
1. Size all wires which carry armature or line current to handle currents AS SPECIFIED BY
NATIONAL, STATE, AND/OR LOCAL CODES. All other wires may be #18 AWG or smaller
as permitted by local code.
2. Separate control wires from all the Armature and AC line wires when routed in conduits
or in wire trays. The Speedmaster has two threaded holes (1/2" NPT) in one endplate,
located near the terminal strip, for this purpose.
WIRING PROCEDURE
The Speedmaster is provided with a fuse in AC line 1 (P1-11). This fuse is sized to open in the
event of a shorted armature or if an armature line is shorted to earth ground. As long as 120
VAC input is connected properly, there is no additional fusing needed.
For 240 VAC applications, an external fuse may be used in AC line 2 (P1-10). This fuse should
be a Bussman ABC10 or LittleFuse 314-010. This added fuse will provide protection on both
AC legs to the control. If you desire not to fuse both legs, the fuse in the control will open in the
event of excessive armature currents.
AC current is desired by motor characteristics. In a small number of applications it may be
necessary to increase fuse value.
CUSTOMER FUSING
Note: The minimum current rating for this Speedmaster control is 150mA.
H.P. Input Voltage Output Voltage Unidirectional Reversing
1/8
1/4
1/3
1/2
3/4
1.0
1.5*
2.0*
* Not available with 120 VAC input - Input voltage determines maximum allowable H.P.
120/240 VAC 0-90/0-180 VDC 174902 174903
240 VAC 0-180 VDC 174902 174903