Bard WE121 Installation Instructions Manual

Contents

Bard WE121 Installation Instructions Manual Manual pdf 14 page image

Manual 2100-384BPage 14 of 19START UPIMPORTANT INSTALLER NOTEFor improved start up performance, wash the indoor coilwith a dishwasher detergent.SERVICE HINTS1. Caution owner to maintain clean air filters at alltimes and also not to needlessly close off supplyand return air registers. This reduces airflowthrough the system, which shortens equipmentservice life as well as increasing operation costs.2. The unit is equipped with a high pressure cut outswitch.3. Check all power fuses or circuit breakers to be suethey are the correct rating.4. Periodic cleaning of the outdoor coil to permit fulland unrestricted airflow circulation is essential.HIGH PRESSURE SWITCHThe WE121 models are supplied with a remote resethigh pressure switch. If tripped, this pressure switchmay be reset by turning the thermostat off then back onagain.SEQUENCE OF OPERATIONCOOLING – Circuit R-Y makes at thermostat pullingin compressor contactor, starting the compressor andoutdoor motor. The G (indoor motor) circuit isautomatically completed on any call for coolingoperation or can be energized by manual fan switch onsubbase for constant air circulation. On a call forheating, circuit R-W1 make at the thermostat pulling inheat contact for the strip heat and blower operation.COMPRESSOR CONTROL MODULEThe compressor control module is optional on themodels covered by this manual. The compressorcontrol is an anti-short cycle/lockout timer with highand low pressure switch monitoring and alarm relayoutput.Adjustable Delay on Make and Break TimerOn initial power up or any time power is interrupted tothe unit the delay on make period begins, which will be2 minutes plus 10% of the delay on break setting.When the delay on make is complete and the highpressure switch (and low pressure switch if employed) isclosed, the compressor contactor is energized. Uponshutdown, the delay on break time starts and preventsrestart until the delay on break and delay on makeperiods have expired.During routine operation of the unit with no powerinterruptions the compressor will operate on demandwith no delay.High Pressure Switch and Lockout SequenceIf the high pressure switch opens, the compressorcontactor will de-energize immediately. The lockouttimer will go into a soft lockout and stay in soft lockoutuntil the high pressure switch closes and the delay onbreak time has expired. If the high pressure switchopens again in this same operating cycle the unit will gointo manual lockout condition and the alarm relaycircuit will energize. Recycling the wall thermostatresets the manual lockout.Low Pressure Switch, Bypass and LockoutSequence (Optional)If the low pressure switch opens for more than 120seconds, the compressor contactor will de-energize andgo into a soft lockout. Regardless the state of the lowpressure switch, the contactor will reenergize after thedelay on make time delay has expired. If the lowpressure switch remains open, or opens again for longerthat 120 seconds the unit will go into manual lockoutcondition and the alarm relay circuit will energize.Recycling the wall thermostat resets the manual lockout.Alarm Relay OutputAlarm terminal is output connection for applicationswhere alarm relay is employed. This terminal ispowered whenever compressor is locked out due to HPCor LPC sequences as described.NOTE: Both high and low pressure switch controls areinherently automatic reset devices. The highpressure switch and low pressure switch cut outand cut in settings are fixed by specific airconditioner or heat pump unit model. Thelockout features, both soft and manual, are afunction of the Compressor Control Module.