Carrier OMNIZONE 50BV020-064 Installation And Service Instructions Manual

Also see for OMNIZONE 50BV020: Operating and troubleshooting guide

Contents

2equipment. Follow all safety codes. Wear safety glasses andwork gloves.GENERALOmnizone™ 50BV indoor packaged units are very flexiblefor a variety of applications. These self-contained units areavailable as water-cooled or remote air-cooled air conditioningunits. The 50BV units are available with either constant vol-ume (CV) or variable air volume (VAV) controls. In addition,the 50BV unit is available as a water-cooled heat pump. Final-ly, Omnizone 50BV units are available in two cabinet styles.Nominal 18 through 30-ton units are constructed in a single-piece, unpainted galvanized cabinet. Nominal 30 through60-ton units are available as modular units, and can be takenapart for easier installation. Modular units are built using an un-painted, galvanized steel cabinet with steel framework, and canbe easily disassembled without breaking the refrigerant lines.See Table 1 for a model number reference by application.Each unit contains multiple scroll compressors piped inseparate refrigerant circuits. Each water-cooled circuit includesa coaxial (tube-in-tube) condenser, TXV (thermostatic expan-sion valve), individual evaporator coils, and all interconnectingpiping. Water-cooled units are shipped fully charged withrefrigerant. Remote air-cooled units are shipped with a nitrogenholding charge.Each unit is equipped with one or two forward-curved cen-trifugal blowers, to ensure quiet air delivery to the conditionedspace. Constant volume units operate at a single, adjustable fanspeed and provide zone temperature control using a standardcommercial thermostat. For VAV applications, the unit is sup-plied with a variable frequency drive(s) (VFD) that automati-cally adjusts blower speed to maintain a constant, adjustableduct static pressure. Compressors are automatically staged toprovide supply air temperature control (VAV applications) orzone temperature control using a two-stage commercial ther-mostat (CV applications).The 50BV units have removable access panels for easyservicing. These panels allow access to controls, compressors,condensers, VFD(s) (if applicable), evaporator motors, blow-ers, belts, pulleys, and refrigeration components.MAJOR SYSTEM COMPONENTSConstant Volume (CV) UnitsMAIN CONTROL BOARD (MCB) — The main controlboard for the 50BVC, E, Q, T, U, and V units provides bothcontrols and diagnostics including:• Condensate Overflow Protection prevents unit operation inthe event that the drain pan clogs (optional sensorsrequired).• Random Start provides a programmable start with a rangeof 30 to 60 seconds.• Anti-short Cycle Timer provides a 5-minute delay to pre-vent compressor short cycling.• Low Pressure Bypass Timer bypasses the low-pressureswitch for 90 seconds to avoid nuisance trips during coldstart-up.• High Pressure Switch Delay is a one-second delay that pre-vents nuisance trips at start-up.• Brownout/Surge/Power Interruption Protection is a20-second moving scale that works in conjunction with therandom start timer to delay unit start when a nuisance lock-out would otherwise have occurred. This allows the waterpumps to restart and establish water flow.• Alarm Output contacts provide remote fault indication.• Test/Service Pin is a jumper that reduces all time delaysettings to 6 seconds during troubleshooting or operationverification.• Reset occurs after a 5-minute delay when a fault conditionoccurs. When the timer expires, the unit will restart. If thesame condition occurs a second time, the unit will be lockedout.• Lockout Reset requires that the unit power be cycled at theunit controller via either the thermostat or unit disconnect.NOTE: The refrigerant circuits on dual compressor modelsare completely independent. If either stage has a fault condi-tion the remaining stage will continue to operate withoutinterruption. A freeze (optional sensor required) or condensateoverflow lockout will shut down both refrigerant circuits.• LEDs are provided for diagnostic purposes.Variable Air Volume (VAV) Units — The 50BVJ, K,W, and X units come equipped with a Carrier 6400 ComfortController and a VFD. Refer to the 50BV,XJ Controls, Opera-tion and Troubleshooting manual for details.NOTE: The VAV units utilize face split coils and should notbe operated below 50% of nominal airflow to prevent coilfreezing.Table 1 — Model Number Reference By Application TypeLEGEND*All units are cooling only unless specified.WARNINGBefore performing service or maintenance operations onunit, turn off main power switch to unit and open all dis-connects. More than one disconnect switch may berequired to deenergize this equipment. Electric shock haz-ard can cause injury or death.CAUTIONUse care in handling, rigging, and setting bulky equipment.MODEL TYPE* AVAILABLE CAPACITY CONSTRUCTION CONTROLS50BVC Water-Cooled 18 to 30 nominal tons Single-piece CV50BVE Remote Air-Cooled 18 to 30 nominal tons Single-piece CV50BVQ Water-Cooled Heat Pump 18 to 30 nominal tons Single-piece CV50BVJ Water-Cooled 18 to 30 nominal tons Single-piece VAV50BVK Remote Air-Cooled 18 to 30 nominal tons Single-piece VAV50BVT Water-Cooled 30 to 60 nominal tons Modular CV50BVU Remote Air-Cooled 30 to 60 nominal tons Modular CV50BVV Water-Cooled Heat Pump 30 to 60 nominal tons Modular CV50BVW Water-Cooled 30 to 60 nominal tons Modular VAV50BVX Remote Air-Cooled 30 to 60 nominal tons Modular VAVCV — Constant VolumeVAV — Variable Air Volume