Thermcraft XST-3-0-36-3V - Manual (Page 141)

Installation and Operation Handbook Safety Information
2408 and 2404 Controller B-3
Power Isolation
The installation must include a power isolating switch or circuit breaker. This device should
be in close proximity to the controller, within easy reach of the operator and marked as the
disconnecting device for the instrument.
Earth leakage current
Due to RFI Filtering there is an earth leakage current of less than 0.5mA. This may affect the
design of an installation of multiple controllers protected by Residual Current Device, (RCD)
or Ground Fault Detector, (GFD) type circuit breakers.
Overcurrent protection
To protect the internal PCB tracking within the controller against excess currents, the AC
power supply to the controller and power outputs must be wired through the fuse or circuit
breaker specified in the technical specification.
Voltage rating
The maximum continuous voltage applied between any of the following terminals must not
exceed 264Vac:
• relay output to logic or dc sensor connections;
• any connection to ground.
The controller should not be wired to a three phase supply with an unearthed star connection.
Under fault conditions such a supply could rise above 264Vac with respect to ground and the
product would not be safe.
Conductive pollution
Electrically conductive pollution must be excluded from the cabinet in which the controller is
mounted. For example, carbon dust is a form of electrically conductive pollution. To secure a
suitable atmosphere , fit an air filter to the air intake of the cabinet. Where condensation is
likely, for example at low temperatures, include a thermostatically controlled heater in the
cabinet.
This product has been designed to conform to BSEN61010 installation category II, pollution
degree 2. These are defined as follows:-
Installation Category II
The rated impulse voltage for equipment on nominal 230V supply is 2500V.
Pollution Degree 2
Normally only non conductive pollution occurs. Occasionally, however, a temporary
conductivity caused by condensation shall be expected.