Unit installation

Installation - Electrical
44 SCXF-SVX01K-EN
Time Clock Option
Time Clock Installation
1. Ensure operating temperature is between 4°F and
131°F.
2. Locate the time clock at least 5 feet away from any large
electrical contact or machinery to avoid possible
electrical interference problems.
3. Provide a separate independent circuit for the time
cloc
k power supply.
4. Since all electronic instruments are sensitive to
v
oltage spikes, pay close attention tot he following:
a. If possible, supply power to the electronic time
cloc
k from a phase different than the one
supplying power to the load.
b. Provide a suitableVaristor or RC network across the
INDUCTIVE LOADS supply terminals to reduce
voltage spikes.
c. Place a diode across the DC OPERATED INDUCTOR
terminals to eliminate back EMF.
d. HIGHLY INDUCTIVE LOADS, especially fluorescent
lights, may require a relay in which case step a. and
c. apply.
The time clock can be surface or flush mounted. Lift off the
front cover and loosen the two screws on opposite
corners. Pull off the base’s plug with a left to right rolling
motion.
Time Clock Installation Checklist
1. Ensure operating temperature is 4°F to 131°F.
2. Locate the time clock at least 5 feet away from any large
electrical
contact or machinery to avoid possible
electrical interference problems.
3. Provide a separate independent circuit for the time
cloc
k power supply.
4. Since all electronic instruments are sensitive to
v
oltage spikes, pay close attention to the following:
a. If possible, supply power to the electronic time
cloc
k from a phase different than the one supplying
power to the load
b. Provide a suitableVaristor or RC network across the
INDUCTIVE LOADS supply terminals to reduce
voltage spikes.
c. Place a diode across the DC OPERATED INDUCTOR
terminals to eliminate back EMF.
d. HIGHLY INDUCTIVE LOADS, especially fluorescent
lights, may require a relay in which case (A) and (C)
apply.
The Digi 20A time clock unit can be surface or flush
mounted. Lift off the front cover and loosen the two screws
on opposite corners. Pull off the base’s plug with a left to
right rolling motion.
Surface Mounting Inside Panel
Place screws through the base’s preset holes and screw to
back of panel or wall.
Wire according to the instructions in the following section.
Depending upon the specific installation, you may find it
more convenient to complete wiring before attaching the
base.
Place the terminal cover over the terminal block by
aligning the two screws with the corner holes in the base.
Push the timer firmly onto the plug in the base.Tighten the
two screws. A base for DIN rail mounting is optional.
Wiring the Time Clock
1. Wire 24, 120, or 220 VAC to input terminals. Make sure
to apply correct voltage. Using incorrect voltage will
void the warranty.
2. Connect wire to the screw terminals according to the
unit
wiring diagrams. Use 12 to 22 AWG wire.
Figure 30. Grasslin time clock option
The time clock option has a programmable timer that is factory
wired to the unoccupied input to provide on/off control.The
time clock will not allow the unit to pass through the night
setback/morning warmup mode, except on units with optional
night heat/morning warm up, or programmable night setback.
See Figure 30, p. 44.
The time clock, a “Digi 20” by Grasslin, is inside the control
panel, but accessible with the control panel door closed.This
same type timer is also used for programmable night setback/
morning warm up. Programming instructions for the “Digi 20”
timer are in the “Programming” section.