Bard H42A2-A Installation Instructions Manual

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Bard H42A2-A Installation Instructions Manual Manual pdf 12 page image

Manual 2100-585BPage 12 of 19WIRING – MAIN POWERRefer to the unit rating plate for wire sizing information andmaximum fuse or circuit breaker size. Each outdoor unit ismarked with a “Minimum Circuit Ampacity”. This meansthat the field wiring used must be sized to carry that amountof current. Depending on the installed KW of electric heat,there may be two field power circuits required. If this isthe case, the unit serial plate will so indicate. All modelsare suitable only for connection with copper wire. Eachunit and/or wiring diagram will be marked “Use CopperConductors Only”. These instructions must be adhered to.Refer to the National Electrical Code (NEC) for completecurrent carrying capacity data on the various insulationgrades of wiring material. All wiring must conform to NECand all local codes.The electrical data lists fuse and wire sizes (75° C copper)for all models including the most commonly used heatersizes. Also shown are the number of field power circuitsrequired for the various models with heaters.The unit rating plate lists a “Maximum Time DelayRelay Fuse” or circuit breaker that is to be used withthe equipment. The correct size must be used forproper circuit protection and also to assure that therewill be no nuisance tripping due to the momentary highstarting current of the 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 “Start Up” section for important information onthree phase scroll compressor start ups.See Tables 3 & 4 for Electrical Specifications.Low Voltage ConnectionThese units use a 24-volt AC low voltage circuit. The“RT” terminal is the 24V transformer output, and the“R” terminal is the 24VAC hot terminal for the operationof the equipment. “RT” and “R” are connected withbrass jumper bar which can be removed and “RT” and“R” connected to external NC (normally closed) contactsuch as a fire/smoke detector that will cause immediateshutdown of the equipment upon activation.“C” terminal is grounded.“G” terminal is the fan input.“Y” terminal is the compressor input for cooling1-Stage units only“W1” terminal is the 1st stage electric heat.“W2” terminal is the 2nd stage heat (if equipped).“E”, “F”, “Y2” & “A” Used with EWM-T Economizer.“1” NO (normally open) lockout alarm.“2” NC (normally closed) lockout alarm.“3” COM lockout alarm.“4” & “5” dirty filter alarm NC (normally closed).“6” Used with MD4000 only; do not use for anything else!“Y1” & “7” Used with EWM-T Economizer; do not usefor anything else!“8” & “9” ECON Fail Alarm.WIRING – LOW VOLTAGE WIRING230/208V, 1 phase and 3 phase equipment dual primaryvoltage transformers. All equipment leaves the factorywired on 240V tap. For 208V operation, reconnectfrom 240V to 208V tap. The acceptable operatingvoltage 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 H model units with Y or Z vent option economizers,refer to the MV4000 Series Lead/Lag Controller manual2100-571 for low voltage connections diagrams.Factory installed Y and Z vent option are wired perFigure 7 of 2100-571.DIRTY FILTER SWITCH & RELAYThese units include a dirty filter switch and relay. Thealarm output of relay is normally closed, open on alarmand is connected to terminals 4 and 5 of the unit lowvoltage terminal block.ECONOMIZER FAIL TIME DELAY RELAYNOTE: Applies only to units with economizers.These units employ a time delay relay used inconjunction with the 100% Economizers to provide aneconomizer fail alarm. The alarm output is connectedto terminals 8 and 9 of the low voltage terminal block.The time delay should be set to no less than 3 minutesto ensure no nuisance alarms.MIS-3054TIMER TO BESET HEREMIS-3054