Bard W18HB-A Installation Instructions Manual

Also see for W18HB-A: Installation instructions

Manual 2100-703Page 15 of 40Wiring – Main PowerRefer to the unit rating plate for wire sizing informationand maximum fuse or circuit breaker size. Eachoutdoor unit is marked with a “Minimum CircuitAmpacity”. This means that the field wiring used mustbe sized to carry that amount of current. Dependingon the installed KW of electric heat, there may be twofield power circuits required. If this is the case, theunit serial plate will so indicate. All models are suitableonly for connection with copper wire. Each unit and/orwiring diagram will be marked “Use Copper ConductorsOnly”. These instructions must be adhered to. Referto the National Electrical Code (NEC) for completecurrent carrying capacity data on the various insulationgrades of wiring material. All wiring must conform toNEC and all local codes.The electrical data lists fuse and wire sizes (75°Ccopper) for all models including the most commonlyused heater sizes. Also shown are the number of fieldpower circuits required for the various models withheaters.The unit rating plate lists a maximum fuse or circuitbreaker that is to be used with the equipment. Thecorrect size must be used for proper circuit protectionand also to assure that there will be no nuisancetripping due to the momentary high starting current ofthe compressor motor.The disconnect access door on this unit may be lockedto prevent unauthorized access to the disconnect. Toconvert for the locking capability, bend the tab locatedin the bottom left-hand corner of the disconnectopening under the disconnect access panel straightout. This tab will now line up with the slot in the door.When shut, a padlock may be placed through the holein the tab preventing entry.See page 21 for important information on three phasescroll compressor start ups.See Table 13 on page 32 for electrical specifications.Wiring – Low VoltageAll 230/208V 1 phase and 3 phase equipment havedual primary voltage transformers. All equipment leavesthe factory wired on 240V tap. For 208V operation,reconnect from 240V to 208V tap. The acceptableoperating voltage range for the 240 and 208V taps are:TAP RANGE240 253 – 216208 220 – 187NOTE: The voltage should be measured at the fieldpower connection point in the unit and whilethe unit is operating at full load (maximumamperage operating condition).For low voltage wiring, an 18 gauge copper, color-codedcable is recommended. See Table 7 on page 17 formore information.Low Voltage ConnectionsThese units use a 24-volt AC low voltage circuit.C terminal is 24VAC common and is grounded.G terminal is the indoor blower input.Y1 terminal is the 1st Stage input for cooling.Y2 terminal is the 2nd Stage compressor input forcooling (if equipped with an economizer).B/W1 terminal is the reversing valve input. Thereversing valve must be energized for heating mode.W2 terminal is the 1st stage electric heat (if equipped).W3 terminal is the 2nd stage of electric heat oremergency heat input (if equipped). This is notapplicable on units with dehumidification.A terminal is the ventilation input. This terminalenergizes any factory-installed ventilation option andindoor blower.D terminal is the dehumidification input. If installed, thisterminal energizes any factory-installed dehumidificationoption.L terminal is 24 volt alarm active output.For units equipped with an alarm relay:1 terminal is the normally closed contact on the relay.2 terminal is the normally open contact on the relay.3 terminal is the common contact on the relay.DDC Connections11 terminal is filter switch, common contact onauxiliary terminal strip (F Control option only)12 terminal is filter switch, normally open contact onauxiliary terminal strip (F Control option only)Unit Shutdown Feature (Standard on All Models)The RT terminal is the 24VAC transformer output,and the R terminal is the 24VAC hot terminal for theoperation of the equipment. RT and R are connectedwith a brass jumper bar which can be removed and RTand R connected to an external NC (normally closed)contact such as a fire/smoke detector that will causeshutdown of the equipment upon activation.Balanced Climate™ Feature (Standard on All Models)All units are equipped with the capability of runningin Balanced Climate mode. This mode is designed toenhance the comfort level by reducing the indoor airflowamount and extending the run time to help extractmore humidity during cooling operation. In heatingmode, the reduced airflow provides a warmer supplyair temperature creating more comfortable heat. TheY1 terminal is the 24VAC input for Balanced Climatecompressor cooling operation. The Y2 terminal is the24VAC input for compressor cooling standard operation.Y1 and Y2 are connected with a brass jumper bar whichcan be removed to enable Balanced Climate mode.