Chromalox PK405-18 - Manual (Page 3)

WIRING
WIRING
Figure 5
Figure 11 Figure 12
Figure 6 Figure 7 Figure 8 Figure 9
1
2
3
4
Line
Single Phase
Load
Pilot
Light
Line
Load
Pilot Light
Single Phase
1
2
3
4
Load
1
2
3
4
Two Circuit
Line
Line Load
Pilot Light
Load
Pilot
Light
1
2
3
4
Control
Voltage
Line
}
Pilot
Light
1
2
3
4
Line
Screwdriver
C
Adjusting
Set Screw
A
Adjusting
Shaft
B
Thermometer
Load (Tank, vat, die or platen)
Figure 13
Figure 14 Figure 15
Three Phase
And Single
Phase When
Load Exceeds
Rating of
Thermostat.
Three Phase
When Load
Does Not
Exceed
Rating of
Thermostat.
Figure 16 Figure 17 Figure 18
LT Models –
A. Entrance for wiring is provided by two 3/4” NPT conduit
holes in end of enclosure. Wiring to control enclosure should
be in moisture-resistant conduit.
B. Remove cover by removing four hexhead screwbolts (see
Figures 8 and 9).
2. Connect wires according to wiring diagrams (Figure 11 thru 15).
Note: Electrical connections should be made with generous loops
of wire – approximately 6” per lead.
3. Replace cover and tighten screws.
4. Replace dial knob and dial knob cover. (NEMA-I models only).
5. Note: If load amperage or voltage rating exceeds switch rating, a
contactor must be used (see Figure 14). Contactors are available
as an optional part.
ELECTRIC SHOCK HAZARD. Disconnect all power
before attempting to calibrate thermostat. Failure to
comply could result in personal injury.
These controls are factory calibrated to the range indicated on the
control adjustment knob.
If calibration is required, either one of two methods may be fol-
lowed:
A. If accurate measurement standards are not available, the ther-
mostat can be readily adjusted to a known temperature stan-
dard such as boiling water (212˚F) (see Figure 16).
B. With the aid of an accurate thermometer or other temperature
measuring device, recalibration may be performed within the
process as in Figure 17.
For either method, the following general calibration procedures
should be followed:
1. Remove knob cover, knob and thermostat housing as per instruc-
tions 3, 4 and 5 under WIRING.
2. Replace knob and turn to highest temperature setting.
3. Slowly turn knob and when controls click “off”, compare the dial
reading against the thermometer reading.
4. If they do not agree –
A. Set dial knob to thermometer temperature reading and pull off
knob.
B. While holding the adjusting shaft (B) tightly, turn small cen-
ter adjusting screw (A) with small screwdriver (C) until ther-
mostat clicks “off” (see Figure 18).
Note: Always use extreme care not to damage the slot in the center
adjusting screw.
C. Each quarter turn of the screw will change the calibration
approximately 30˚F:
– Clockwise to decrease temperature
– Counterclockwise to increase temperature
D. Recheck calibration and repeat process if closer calibration is
required.