LOWER
UPPER
LOWER
RAISE
INPUT 120 V.
50/60 Hz
RESISITOR
DRIVE MOTOR
CAPACITO
R
LIMIT SWITCH
C
NC
NO
LIMIT SWITCH
C
NC
NO
1
2
3
PERCENT
OF RA
TED LOAD
104°F 122°F 140°F
158°F 176°F 194°F
100
80
60
40
20
0
40°C 50°C 60°C 70°C
80°C 90°C
AMBIENT TEMPERATURE
FIGURE C
BOTTOM OF STANDOFFS
3.88"
[98.55]
“F”
“F”
10.81"
[274.57]
TOP
HOLES FOR 1/4"
BOLTS AS INDICATED
“E”
“E”
7.38"
[187.45]
“D”
“D”
6.12"
[155.45]
“C”
“C”
3.94"
[100.07]
“B”
“B”
2.69"
[68.32]
“A”
“A”
1.06"
[26.92]
INSPECTION
A POWERSTAT Variable Transformer is a precision product packed with care.
When unpacking, examine carefully for any shipping damage. Inspect the
brush contact with particular care. The “Damage and Shortage” Instructions
packed with the unit outline the proper procedure to follow if any parts are
damaged or missing.
INSTALLATION
NOTE-
The unit should be protected from any dust or debris that may be
encountered while drilling holes, installing wiring, etc., during installation.
MANUALLY OPERATED ASSEMBLIES
Manually operated single units are designed for back-of-panel mounting.
If they are to be bench or wall mounted, some cover should be provided
to support the dial and prevent contact with the electrically “hot” radiator
and commutator.
HARDWARE
Drilling Template No. 1 shows standard 4-hole mounting and an alternate
3-hole mounting. For standard 4-hole mounting use 1/4” bolt of appropriate
type and length. The alternate mounting scheme allows the mounting screws
to be hidden by the dial but requires 1/4 - 20 flat head type screws whose
length can only be 1/8” to 3/16” longer than the thickness of the mounting
panel. To accommodate longer length screws, use 1/4” flat washers as
spacers between unit and the back of the panel. Three 6-32 x 3/16” binding
head screws are provided for dial mounting.
ACCESSORY TERMINAL PACK
An accessory terminal pack, ordered separately, contains seven terminal
adapters for quick-connect terminations or for easy soldering (only three
adapters are required for any one connection).
SINGLE UNITS
BENCH OR WALL MOUNTING
1. Using Drilling Template No. 1, locate and drill the desired set of
mounting bolt holes (4 holes “A” or three holes “B”).
2. Insert the shaft and adjust it so it will protrude about ¾” through the
dial after installation. Tighten the setscrews.
3. Place the unit in position. Insert and tighten the mounting screws.
4. Mount the dial and its support(s). Place the knob on the shaft and position
the pointer correctly in relation to the brush position and the dial indications.
Tighten the knob setscrews.
BACK-OF-PANEL MOUNTING
1. Using Drilling Template No. 1 locate and drill the desired set of mounting
bolt holes (four holes “A” or three holes “B”), the three dial screw holes
“C” and the center shaft hole. The dial screw holes must be tapped to
accommodate the 6-32 screws supplied. Maximum panel thickness is
1/2 inch.
2. Insert the shaft and adjust it so it will project about ¾” through the
panel after installation. Tighten the setscrews.
3. Place the unit in position behind the panel. Insert and tighten the
mounting screws.
4. Mount the dial on the panel. Place the knob on the shaft and position the
pointer correctly in relation to the brush position and the dial indications.
Tighten the knob setscrews.
GANGED ASSEMBLIES
Manually operated ganged assemblies are designed for back-of-panel
mounting. If they are to be mounted in an exposed position, some cover
should be provided to prevent contact with the electrically “hot” radiator
and commutator. Due to the weight of ganged assemblies, the four holes
“A” of Drilling Template No. 1 are recommended for mounting.
HARDWARE
Three 6-32 x 3/16” binding head screws are provided for dial mounting.
Four 1/4”-28 x 1/2” flat head screws are provided for mounting in panels 1/4”
to 3/8” thick. For thinner panels use 1/4” flat washers as spacers between
the unit and the panel. For thicker panels use 1/4”-28 screws 1/8” to 1/4”
longer than the panel thickness.
ACCESSORY TERMINAL PACK
An accessory terminal pack, ordered separately, contains seven terminal
adapters for quick-connect terminations or for easy soldering (only three
adapters are required for any one connection).
BACK-OF-PANEL MOUNTING
1. Using Drilling Template No. 1, locate and drill the four mounting bolt
holes “A”, the 3 dial screw holes “C” and the center shaft hole. The
dial screw holes must be tapped to accommodate the 6-32 screws
supplied. Maximum panel thickness is 1/2 inch.
2. Loosen the knob setscrews and remove the knob. Remove the dial.
3. Loosen the shaft setscrews in the hub of each radiator and adjust the
shaft so it will project about ¾” through the panel after installation.
Tighten the setscrews on the first unit. Turn all radiators to the extreme
limit of travel (zero position) and tighten the shaft setscrews on the
remaining unit(s).
4. Place the unit in position. Insert and tighten the four ¼”-28 mounting
screws. A 3-gang assembly, because of its added length and weight,
requires extra support in the form of a bracket or shelf.
5. Mount the dial on the panel. Place the knob on the shaft and position
the pointer correctly in relation to the brush position and the dial
indications. Tighten the knob setscrews.
MOUNTING ON SIDE BRAKETS
1. Using Drilling Template No. 2, locate and drill the proper set of
mounting holes. BE SURE TO USE THE PROPER SET OF HOLES.
2. Loosen the shaft setscrews in the hub of each radiator and adjust
the shaft so it will project about ¾” through the dial after installation.
Tighten the setscrews on the first unit. Turn all radiators to the extreme
limit of travel (zero position) and tighten the shaft setscrews on the
remaining unit(s).
3. Insert the two top mounting bolts and screw them in part way.
4. Place the unit in position and insert the two bottom bolts. Tighten all
the bolts. Mount the dial and its supports. Place the knob on the shaft
and position the pointer correctly in relation to the brush position and
the dial indications. Tighten the knob setscrews.
MOUNTING ON STANDOFFS
1. Using Drilling Template No. 1 locate and drill the four mounting bolt
holes “A”.
2. Loosen the knob setscrews and remove the knob. Remove the dial.
3. Loosen the shaft setscrews in the hub of each radiator and adjust
the shaft so it will project about ¾” through the dial after installation.
Tighten the setscrews on the first unit. Turn all the radiators to the
extreme limit of travel (zero position) and tighten the shaft setscrews
on the remaining unit(s).
4. Place the unit in position. Insert and tighten the mounting bolts. A 3-
gang assembly, if mounted on a vertical panel, requires extra support
in the form of a bracket or shelf.
5. Mount the dial and its supports. Place the knob on the shaft and
position the pointer correctly in relation to the brush position and the
dial indications. Tighten the knob setscrews.
MOTOR-DRIVEN ASSEMBLIES
Motor-driven POWERSTAT Variable Transformers of the 21, 21-40 and 22
Series, both single units and ganged assemblies, may be mounted on side
brackets or on standoffs in the same manner as manually operated ganged
assemblies. 3-gang assemblies, however, have 3 side brackets, requiring 6
mounting bolts as shown in Template No. 2.
MAINTENANCE
With ordinary care, a POWERSTAT Variable Transformer should require no
servicing except possible replacement of the brush assembly. The brush
should be inspected periodically and replaced if arcing takes place or if
it is badly worn. Because the brush must be of a special material, replace
only with the Superior Electric brush assembly listed below. The assembly is
designed to assure perfect contact of the brush to the commutator regardless
of brush position and length of time in use. Take care to avoid scraping,
scratching or marring the commutator surface.
Follow these steps to install a new brush assembly.
1. Unfasten the brush assembly anchor screws and discard the old brush
assembly.
2. Insert the new brush assembly in the radiator slot, replace the anchor
screws and tighten to the radiator. Be sure the back end of the brush
strap is under the projection at the rear of the radiator brush slot.
3. Raise the brush and place a piece of crocus cloth or very fine
sandpaper between the brush and the commutator so the smooth
side is against the commutator and the abrasive side is toward the
brush.
4. While holding the cloth or sandpaper in place, rotate the radiator
through a short arc. Blow out the excess carbon particles.
CONNECTIONS AND RATINGS
Important connection notes. Please read carefully.
• CONNECTIONS AND RATINGS given in these instructions are
those most commonly used. In addition, all ganged units may be
connected so that the units operate electrically independent on a
common shaft. When this is desired, connections and ratings for
the individual units may be obtained from the RATINGS CHART
and CONNECTION DIAGRAMS of the single unit.
• For
ambient temperatures
between -20
°
C and +50
°
C use
current ratings given in the charts. Figure C shows the output
current de-rating required above 50
°
C.
• Coil to terminal connections for all 21, 22 and 21-40 Series units
are shown in Figures A.
• The CONNECTION DIAGRAMS are labeled “L” for Line
Connections and “B” for Boost Connections.
• Clockwise (CW) and counterclockwise (CCW) rotation connections
shown in the Ratings Chart and Connection Diagrams are for
motor driven units and manual units with the knob on the radiator
end. For connections with the knob on the base end, use the
shown CCW connection for the CW operation, and shown CW
connection for the CCW operation.
• Fuses are recommended on all units as shown (
§
). Recommended
fuses are 18 ampere on 21-40, 5 ampere for the 21, and 3 ampere
on the 22. If used for constant impedance load connection the
fuses can be increased to a 25 ampere on the 21-40, 8 ampere
on the 21, and 4 ampere on the 22.
•
COMMON
shown in the connection diagrams is used as third
leg in 3-phase open delta, or neutral in single-phase 3-wire
and 3-phase 4-wire wye configurations. COMMON is not used
in single-phase 2-wire or 3-phase 3-wire wye configurations.
Jumper(s) provided in standard common position should be
moved or removed as required.
• Motor drive wiring is shown in Figure B.
BRUSH ASSEMBLY
Whenever unusual mechanical or electrical difficulties are encountered in
the operation or installation of your POWE R STAT Variable Transformer,
consult Superior Electric.
DESCRIPTION
REPLACEMENT BRUSH ASSEMBLIES
MODEL NUMBER
PART NUMBER
21
21-40
22
060098-001
060098-002
060117-001
RB21/Brush Assembly
RB21-40/Brush Assembly
RB22/Brush Assembly
for INSTALLATION OPERATION and MAINTENANCE
INSTRUCTIONS
POWERSTAT
®
The right to make
engineering refinements
on all products is reserved.
Dimensions and other
details are subject to
change.
Telephone and Fax Numbers
Telephone 860-507-2025
Fax 860-507-2050
Toll-Free (in USA and Canada only)
Telephone 1-800-787-3532
Fax 1-800-821-1369
Email and Website
Email [email protected]
Website www.superiorelectric.com
Printed in USA
2100 WEST BROAD STREET
ELIZABETHTOWN, NC 28337 USA
002105-091 REV M ©2020
ECN 97544
VARIABLE TRANSFORMERS
WITH POWERKOTE
®
COILS
21, 21-40 and 22 Series
5. Remove the cloth or sandpaper and rotate the radiator over the full
range several times to check for smooth travel of the brush over
the commutator surface. The brush should fit flat over the entire
commutator range. No space should be visible between the brush
and the surface.
#
FIGURE B - MOTOR DRIVE WIRING
FIGURE A
MOUNTING TEMPLATE NO. 2
NOTE:
All dimensions are in inches [millimeters]
2100 WEST BROAD STREET • ELIZABETHT
OWN
, NC 28337 USA
www
.superiorelectric.com
002105-091 REV M
SUPERIOR ELECTRIC NEW SYMBOL LAYOUT ISOLATED OUTLINED TYPE REVERSED
