Water-Cooled Condensers - HTS

Water-cooled condensers can be piped for use with cooling towers or well water. Consider freeze protectionand scaling problems on cooling tower applications. Contact the cooling tower manufacturer for equipmentcharacteristics and limitations for the specific application.Head pressure control must be provided if the entering condenser water can fall below 65F. The MicroTechII unit controller can provide this function, using entering condenser water as the control point. The controlwill work with or without the optional condenser manifolds. The water sensors are factories-installed. Thecontroller setpoints have to be adjusted for water control and certain output wiring connections made to thetower components.Ice Storage ApplicationsThe MicroTech II controller has logic to change setpoints from the low temperature ice-making mode tohigher, normal comfort cooling setpoints. It is important that the MicroTech II controller receive a 0 VAC(normal operation) to 24 VAC (ice mode) signal to convert from ice mode to normal operating mode. TheMicroTech II controller includes logic to keep the compressors fully loaded when operating below 30F (-1.1C). The double insulation thickness option is recommend to prevent sweating.Two Pipe SystemsWhen the same two pipes are used for both heating and cooling water, several limitations should be observed.The maximum allowable temperature entering the evaporator in a non-operating mode is 100F. For unitoperation and system changeover from heating to cooling, the maximum allowable temperature entering theevaporator is 90F. System controls provided by others must prevent chiller operation until the looptemperature drops to 90F.Electrical ConnectionEvery WGS chiller requires field installation of the main supply power plus mandatory flow switch interlockand optional pump starter auxiliary contact interlock. A control circuit transformer installed at the factoryeliminates the need for field installation of a separate 115V supply to the control circuit. A separate 115V fieldconnection to the control circuit can be substituted. A system time clock and remote on-off switch can also befield installed.See Figure 10 or Figure 11 on pages 37 and 38 for field electrical hookups (water-cooled or remote condenserrespectively). Each unit is provided with its specific wiring diagram in the control panel. All wiring must bedone according to local and national codes.Main Power Supply Disconnect SwitchEvery WGS unit with the standard multi-point power supply is equipped with power blocks and nocompressor circuit breakers. Single-point power connection is available as an option using one power blockand individual compressor circuit breakers.A factory-installed non-fused disconnect switch with a through-the-door handle (required to meet NEC Codefor disconnects) is available as an option with single- or multiple-point power supply. The single-pointdisconnect includes individual compressor circuit breakers. The disconnect switch(s) is properly sized for themodel and voltage supplied.A field-supplied and installed remote disconnect switch can also be used.Control CircuitA control power transformer is standard equipment on WGS units. Terminals are provided in the unit controlcenter (terminals TB1 and TB1-2) for field connection to a remote 115V power supply if desired.Terminals are also provided for field connection of the chilled water flow switch, unit time clock, ambientthermostat and/or remote on/off switch.Condenser Pump InterlockThe condenser water pump should be interlocked to cycle with the compressor(s). This will prevent therefrigerant pressure from being overly depressed during the off cycle and allows the energy savings of pumpshutdown. Interlock terminals are provided in the unit control panel.Catalog WGS-1 WGS 130A – 190A 47