RKI Instruments M2 for 12 VDC - Manual (Page 33)

M2 Transmitter Operator’s Manual, 12 VDC Operation 28
Replacing Components of the M2
Replacing LEL Detector
1. Turn off or disconnect power to the M2.
2. Remove the junction box cover.
3. Grasp the control PCB by its edges.
4. Gently pull until the control PCB is pulled away from the banana jacks. Take care not
to pull too hard and damage the cable which connects the control and terminal PCB’s.
5. Let the control PCB hang by the cable. The terminal strips are now visible on the
terminal PCB. The control PCB may be left hanging while wiring is done. If desired,
the control PCB may be disconnected from the cable and set aside while wiring.
6. Remove the detector terminal strip from its socket.
7. Disconnect the detector leads from the detector terminal strip. Note the position of the
color-coded leads as you remove them.
8. Unscrew the detector from the junction box.
9. Guide the replacement detector leads through the bottom conduit hub of the junction
box, then screw the mounting threads of the detector into the conduit hub.
10. Connect the detector leads to the detector terminal strip as follows:
Red wire to terminal labeled LEL RED, white to terminal labeled LEL WHT, green
wire to terminal labeled LEL GRN, black wire to terminal labeled LEL BLK.
11. Re-install the detector terminal strip into its socket.
12. Re-install the control PCB (and ribbon cable if necessary). Be sure the ribbon cable is
routed down below the control PCB so it will not be damaged by the cover when it is
screwed back on.
13. Secure the junction box cover to the junction box.
14. Turn on or reconnect power to the M2.
CAUTION: Allow the replacement detector to warm up for 15 minutes before you continue
with the next step.
15. Calibrate the replacement detector as described in “Calibration” on page 25.