Installation
4/07 UDC2500 Universal Digital Controller Product Manual 17
2.6 Wiring
2.6.1 Electrical Considerations
Line voltage wiring
This controller is considered “rack and panel mounted equipment” per EN61010-1,
Safety Requirements for Electrical Equipment for Measurement, Control, and Laboratory
Use, Part 1: General Requirements. Conformity with 72/23/EEC, the Low Voltage
Directive requires the user to provide adequate protection against a shock hazard. The
user shall install this controller in an enclosure that limits OPERATOR access to the rear
terminals.
Mains Power Supply
This equipment is suitable for connection to 90 to 264 Vac or to 24 Vac/dc 50/60 Hz,
power supply mains. It is the user’s responsibility to provide a switch and non-time delay
(North America), quick-acting, high breaking capacity, Type F (Europe), 1/2A, 250V
fuse(s), or circuit-breaker for 90-264 Vac applications; or 1 A, 125 V fuse or circuit
breaker for 24 Vac/dc applications, as part of the installation. The switch or circuit-
breaker shall be located in close proximity to the controller, within easy reach of the
OPERATOR. The switch or circuit-breaker shall be marked as the disconnecting device
for the controller.
CAUTION
Applying 90-264 Vac to an instrument rated for 24 Vac/dc will severely
damage the instrument and is a fire and smoke hazard.
When applying power to multiple instruments, make certain that sufficient current is
supplied. Otherwise, the instruments may not start up normally due to the voltage drop
caused by the in-rush current.
Controller Grounding
PROTECTIVE BONDING (grounding) of this controller and the enclosure in which it is
installed shall be in accordance with National and Local electrical codes. To minimize
electrical noise and transients that may adversely affect the system, supplementary
bonding of the controller enclosure to a local ground, using a No. 12 (4 mm
2
) copper
conductor, is recommended.
Control/Alarm Circuit Wiring
The insulation of wires connected to the Control/Alarm terminals shall be rated for the
highest voltage involved. Extra Low Voltage (ELV) wiring (input, current output, and
low voltage Control/Alarm circuits) shall be separated from HAZARDOUS LIVE (>30
Vac, 42.4 Vpeak, or 60 Vdc) wiring per Permissible Wiring Bundling, Table 2-5.
Electrical Noise Precautions
Electrical noise is composed of unabated electrical signals which produce undesirable
effects in measurements and control circuits.