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51-52-33-157 Rev. 6
General
wiring
considerations
Use only Class I, Division 2 wiring methods as specified in the National Electrical Code NFPA70
and the Canadian Electrical Code C22.1.
The Control Station cables contain low voltages. Keep cables away from high voltage wires that can
cause interference.
CE testing was performed with shielded, twisted pair cables. For noise reduction tips, see
Honeywell document 51-52-05-01, How to Apply Digital Instrumentation in Severe Electrical
Noise Environments.
ATTENTION
The emission limits of EN 55011 (CISPR11) are designed to provide reasonable protection
against harmful interference when this equipment is operated in an industrial environment.
Operation of this equipment in a residential area may cause harmful interference. This
equipment generates, uses, and can radiate radio frequency energy and may cause
interference to radio and television reception when the equipment is used closer than 30
meters to the antenna (e). In special cases, when highly susceptible apparatus is used in close
proximity, the user may have to employ additional mitigating measures to further reduce the
electromagnetic emissions of this equipment.
3. Connect to earth ground
The back of the unit has a chassis ground terminal identified with the symbol
. Connect this terminal to
earth ground (protective earth).
The chassis ground is not connected to signal common of the unit electronics. Maintaining isolation between
earth ground and signal common is not required to operate the unit, but when connecting the HC900
controller to the unit using the recommended shielded CAT5 Ethernet cable, a path to earth ground is created
via the Ethernet shield of the controller. Other equipment connected to the unit may require isolation
between signal common and earth ground. To maintain isolation, care must be taken when connections are
made to the unit. For example, a power supply with isolation between its signal common and earth ground
must be used.
Connecting a device via a USB cable may also connect signal common and earth ground. The shield of the
USB’s connector at the host may be connected to earth ground. A USB’s shield may also be connected to
signal common.
4. Mount and connect power supply
The Control Station requires a 24 VDC power supply rated at 29 W or more. Your unit may draw
considerably less than rated power depending upon the options being used. As additional features are used
your unit will draw increasing amounts of power. Items that could cause increases in current are additional
communications, Flash Memory Module, and other features programmed using Station Designer software.
It is important that the power supply is mounted and wired correctly if the unit is to operate reliably. Please
take care to observe the following points.
A 10” model requires a minimum of 29 Watts of power supply and a 15” model requires a minimum of 46
Watts of power supply.
The power supply should be mounted close to the unit. Recommended not more than 6 feet (1.8 m) of cable
between the supply and the Control Station. Ideally, the shortest length possible should be used.
A power supply with isolation between its signal common and earth ground must be used.
The wire used to connect the power supply to the Control Station should be at least 22-gage wire. If a
longer cable run is used, a heavier gage wire should be used.
The routing of the cable should be kept away from large contactors, inverters, and other devices which may
generate significant electrical noise.
