Wiring Guidelines - Honeywell CM4 Technical Handbook

CM4 Four-Point Continuous Monitor

3.10.3 Wiring Guidelines

To wire the alarm relays:
• Use shielded cable or conduit. See
cable information.
CAUTION
Failure to replace and retighten hardware after servicing can
adversely affect instrument performance and EMC compliance. Make
certain all fasteners are reinstalled and firmly tightened. This will
ensure a proper ground.
• Connect grounds to stud at lower left corner of the I/O panel.
See Figure 3-11
• Use #8 hardware provided
• Use a single, solid or stranded wire (not exceeding 14 gauge)
per terminal block connection
• Do not switch DC current with the relay contact unless you are
using counter electromotive force (CEMF) protection such as
a suppression diode
• Do not use the CM4 power supply for external alarm power
IMPORTANT:
Make sure all connections comply with applicable RFI/EMI standards.
NO C NC
!
REFER TO USER MANUAL
CM4 Technical Manual
Appendix E for additional
NO C NC NO C NC NO C NC NO C NC
1 2 3 4
RY1 RY3 RY5 RY7
LEVEL 1 POINT ALARMS
WARNING
• FUSES BELOW FLAPS
EXTERNALLY APPLIED VOLTAGES MAY BE PRESENT AT ALARM TERMINAL BLOCK WITH
!
INSTRUMENT DISCONNECTED. DISCONNECT AT SOURCE PRIOR TO SERVICING.
GENERAL ALARMS
LEVEL 1 LEVEL 2
RY2 RY4 RY6
NC C NO NC C NO NC C NO
Ground Lug
Figure 3-11: I/O Panel Connections
3.11 Wiring Optional Current Loop (4-20 mA Output)
Each current loop output produces a current which varies linearly
from 4 to 20 mA as the concentration of gas varies from zero to a
user-programmable full scale concentration. The gas concentration
for 20 mA full scale defaults to the full scale of the gas, but can be
configured lower.
Furthermore, the CM4 can be configured lower to reduce these output
currents to 2 mA if certain faults occur. These outputs will drop to zero
mA after a power failure.
The current loop connection points are located on the I/O Panel.
The impedance range of the analog output is 100-800 ohms.
All wiring should follow the wiring guidelines described in Wiring
Guidelines (Section 3.10.3).
NO C NC NO C NC NO C NC
1 2 3 4
RY9 RY11 RY13 RY14
LEVEL 2 POINT ALARMS
• 2A 125 VAC MAX. CONTACT RATING
!
INSTRUMENT STATUS
MAINTENANCE FAULT WATCH DOG
RY8 RY10 RY12
NC C NO NC C NO NC C NO
3-13
CAUTION
REPLACE FUSES WITH SAME
TYPE AND RATING SPECIFIED
PT.
REMOTE INPUTS
1
2
N.O. TB20
SW.
TB19
3
TB
18
4
PT.1 PT.2 PT.3 PT.4
TB
TB TB
15
16 17