System Operation, Testing and Maintenance
9.0SYSTEM OPERATION, TESTING AND MAINTENANCE
This section describes system testing, maintenance and replacement procedures. Use copies of the Maintenance Inspection Checklist to record preventive maintenance inspections.
! WARNING
Risk of electric shock. Can cause injury or death.
Open all local and remote electric power disconnect switches before working within the electrical enclosures.
The Liebert microprocessor control does not isolate power from the unit in the Unit Off mode. Some internal components require and receive power even during the Unit Off mode. The line side of the disconnect switch on the front of the unit contains live high voltage. The only way to ensure that there is NO voltage inside the unit is to install and open a remote disconnect switch and check the internal power supply wires with a voltmeter.
9.1System Testing
9.1.1Environmental Control Functions
The performance of all control circuits can be tested by changing the set points, which activates each of the main functions.
9.1.2Cooling
To test the cooling function, set the set point to a temperature of 10°F (5°C) below room temperature. A call for cooling should register and prompt the equipment to begin cooling cycle. (Disregard any temperature alarms). Upon completion of testing, return set point to the desired temperature.
9.1.3Heating
Reheat may be tested by setting the set point 10°F (5°C) above room temperature. A call for heating should register and prompt the equipment to begin heating cycle. (Disregard any temperature alarms). Upon completion of testing, return set point to the desired temperature.
9.1.4Humidification
To check humidification, set the humidity set point at R.H. 10% above the room humidity reading. After a short delay, the canister will fill with water and steam will be produced. Upon completion of testing, return the humidity set point to the desired humidity.
9.1.5Dehumidification
The dehumidification performance can be tested by setting the humidity set point at R.H. 10% below room relative humidity. The compressor should turn on. Upon completion of testing, return humidity set point to the desired humidity.
9.1.6Remote Shutdown
A connection point is provided for remote shutdown devices supplied by the customer. This terminal strip is located on the printed circuit board. (Terminals
9.2Maintenance and Component Operation
9.2.1Electric Panel
The electric panel should be inspected on a
9.2.2Filters
Filters are usually the most neglected item in an environmental control system. In order to maintain efficient operation, they should be checked monthly and changed as required. ALWAYS TURN POWER OFF BEFORE REPLACING FILTERS.
Filters are replaced by opening the hinged door on the return air filter box.
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