Sterling HS - Manual (Page 19)

19
VARIABLE SPEED CONTROL
115 Volt Only (optional)
The solid state speed controller may be installed at any
convenient location and is suitable for surface or fl ush
type mounting. A Standard electrical single or double
gang wall box is recommended as in Figure 23.
Figure 23
Wiring Diagram of Speed Control Installation
Installation procedure:
1. Attach the control’s leads to the electrical leads in
the control box using wire nuts. The speed control
is to be wired in series with the motor. See wiring
diagram in Figure 23.
2. Make certain wire nuts are tight with no copper wire
being exposed.
3. Place wires and wire nuts back into box allowing
room for the control to fi t in box also.
4. Mount speed control to box using number 6
fl athead screws provided.
Setting the control:
1. Turn the control shaft fully clockwise. If the motor
is not running at the desired low speed, adjust the
trim on the face of the control for low speed setting
using a small screwdriver.
2. Rotate the control shaft counter clockwise. The
speed will increase smoothly from minimum to
maximum and then switch off.
3. Mount face plate with screw provided and attach
control knob.
STRAP-ON WATER CONTROL
A SPDT strap-on type hot water control with 100° to
240°F (38 to 116°C) rated at 10 amps at 120V is also
available. Control can be used for direct or reverse acting
applications as high or low limit.
STEAM PRESSURE CONTROL
SPDT switch opens on a rise in pressure. Control is
automatically reset, has a range of 0 to 15 PSIG (0
to 103 kPa) and has an adjustable differential. Other
actions, ranges, circuits and manual reset models
are available on request.
OPTIONS
HORIZONTAL AND VERTICAL LOUVERS
Horizontal louvers are standard on all models. Vertical
louvers are an optional accessory on all models. Vertical
louvers are installed on built to order units or shipped
loose for fi eld installation.
Figure 24
Horizontal and Vertical Louver Mounting
THERMOSTATS
Line voltage wall thermostats are in stock for immediate
shipment. All models are SPST with bimetal thermometer,
knob-type set point adjustment, 40 to 90°F (5 to 30°C)
range and selector switches. Standard duty models with
“off-auto” and “auto-off-fan” and a heavy duty model
with “auto-off-fan” switching are available. Other models
available on request. Plastic tamperproof one size fi ts all
thermostat guards are also available.
MANUAL STARTERS
Single and three-phase models are available. Standard
models are single-speed, toggle-operated, NEMA Type
1 and are surface-mounted.
WALL MOUNTED SPEED CONTROLLERS
Units with standard motors up to Model 108 (115/1/60)
can be operated at reduced speeds by addition of
optional speed controller. Controller is 5 amps, pre-set
at factory for maximum and minimum speeds, with
intermediate speeds infi nitely controllable. All 1/3, 1/2
HP and 230V motors operate only at rated speed and
CFM – See Charts.
NOTICE: When using electrical accessories, always
refer to the accessory manufacturer’s installation
manual for proper use, location and wiring
instructions.