Myron L 729II - Manual (Page 39)

by pulling lightly on the wires. It may be necessary
to use a small flat screwdriver to slightly spread the
retaining ring. See figure III.D.1.
b. Remove Set Point Switch from the front panel,
figure III.D.1, by rotating the round bezel nut CCW
on the front as shown in figure III.D.2.
c. Remove SCH harness from SC Module by on pulling
harness.
d. Set SCH harness aside, it is no longer used.
4. Remove Primary or Main CB alarm/control LED and Set
Point Switch from lower location on front panel.
a. Carefully remove the RED LED from the front panel
by pulling lightly on the wires. It may be necessary
to use a small flat screwdriver to slightly spread
the retaining ring. See figure III.D.1.
b. Remove Set Point Switch from the front panel, figure
III.D.1, by rotating the round bezel nut CCW on the
front as shown in figure III.D.2.
5. Re-install Primary or Main CB alarm/control LED and Set
Point Switch into UPPER location as shown in figure
III.D.6.
6. Install TH/THO harness to front panel. See figure III.D.6.
a. Install Set Point Switch into the LOWER CENTER
switch location.
b. Press RED LED into the LOWER location.
7. Remove SPC jumpers (2) from SC/SCO Second
Alarm/Control Module, see figure III.D.3 for SPC jumper
location.
8. Install TH/THO harness to SC/SCO Second
Alarm/Control Module.
a. Attach BLACK 90° connector with four wires to SPC
location with the connector 90° to the SC as shown
in figures III.D.7 & III.D.8.
b. Press WHITE connector with two wires and one
jumper into the SC - it is directional, as shown in
figures III.D.7 & III.D.8.
9. Turn SCO Set Point control fully counter clockwise - it
may be 30 turns - or until it clicks. See figure III.D.7 for
location.
10. The GREEN LED stays in the same location.
11. Locate and remove JUMPER from the Temperature
(TPO) Module as shown in figure III.D.5.
12. Attach Brown 5 wire connector to the TPO Module as
shown in figure III.D.9.
13. Add TEMPERATURE label to LOWER front panel
covering the “LOW” as shown in figure III.D.10.
14. Attach control leads to RELAY #2 as shown in figure
III.D.3.
15. Continue to Set Point Conversion or skip to “SPECIFIC
OPTION” Module Set Point adjust.
WARNING: There are two (2) O-rings installed on the switch,
one(1) on the threaded shank and the other is under the push
button. Both of these must be reinstalled to maintain IP65/NEMA
4X ratings. See figure III.D.4.
b. LOW Primary Control
If the front panel has all ready been removed from the enclosure
skip to step 3.
1. Using a standard slot screwdriver remove the
screws on the front panel.
2. Carefully wiggle the front panel to loosen the gasket and
pull gently toward you. Do not pull more than about 8
inches/20CM or you could damage the wiring harness.
3. Remove SCH harness from front panel, figure III.D.11,
and SC/SCO Second Alarm/Control Module, figure III.D.3
for locations.
a. Carefully remove the UPPER RED LED from the
front panel by pulling lightly on the wires. It may be
necessary to use a small flat screwdriver to slightly
spread the retaining ring. See figure III.D.1.
b. Remove UPPER Set Point Switch from the front
panel by rotating the round bezel nut CCW on the
35
SPC
INC
PA
SCO SET POINT #2 ADJUST
(TURN CONTROL FULL CCW)
CM
NO NC
Figure III.D.3
SC/SCO MODULE
(SECOND ALARM/CONTROL)
MAIN CIRCUIT BOARD NOT SHOWN FOR CLARITY
COM
RELAY #2
}
NO
NC
REMOVE SCH HARNESS
REMOVE BOTH SPC JUMPERS
SWITCH
FRONT PANEL
BEZEL PUSH
BUTTON
O-RING O-RING
SWITCH and O-RING ASSEMBLY
Figure III.D.4
BR
B
L O
R
- +
SPC
Figure III.D.5
TEMP
CONTROL
HARNESS
FS
DISPLAY
SELECT
TEMP
SENSOR
BRN
BLU
INC
INC
DEC DEC
JUMPER
REMOVE TO INSTALL
CONTROL HARNESS
TP/TPO MODULE
+
0-5VDC
-