INTRODUCTION

PETRA Water Source Package (PWSP) is the indoor unit in the ESC system. It is a self- contained reverse cycle A/C unit that supplies either cold or warm air to the application space with highly efficient performance using an internal room thermostat (controller). This compact unit has different designs such as free- standing, ducted, concealed and floor mounted cabinet types to fit all customer requirements.

The compact design of the PWSP makes installation easier by eliminating refrigerant lines between the indoor and outdoor unit in residential applications, shops, hospitals, and restaurants.

Also, the design of the PWSP focuses on simplicity of maintenance since all accessible components are situated in one place. PWSP has a special noise isolating patented design compartment surrounding the compressor, which achieves the lowest noise level in the market for such applications.

PWSP series includes 15 sizes ranging from 5.3 to 98.5 kW with air flow from 1019 to 16990 m3/hr with minimal noise through suction, discharge and radiation sections. The unit models (PWSP15 - PWSP65) have three speed centrifugal fans (low, mid and high).
 

FEATURE AND BENEFITS

Unit Types

PETRA offers you different choices to meet your requirements:

• Horizontal Units: Designed for installation in the ceiling plenum where there is enough space available
  on-site (suitable for offices, apartments, hotels, and schools)

• Decorative Free Standing: Designed to be installed in corners where there is not enough floor space on-site
  (suitable for open spaces like restaurants, hotels, and offices)

• Vertical Stack Units: Suitable for multi-story buildings like apartment, hotels, hospital, and schools. Using vertical
  stack units minimizes piping and decreases cost of installation.

• Decorative Floor Type: For decorative installation on floors and is suitable for installation where there is not sufficient
   space for duct work.
 

Hermetic Compressor

•  Low sound compressor: with low discharge pulse levels which ensures quiet operation

•  High efficiency: with high efficiency ratings

•  Low foaming mineral based lubricant

•  Full maximum load rundown capability

•  Internal inherent line break motor protection with start winding protection on single phase models

(For horizontal units PWSP 15-65):

•  Compressor acoustics compartment

•  Sound jacket kit for compressor
 

Applications and Specifications:

•  All compressors used are approved to operate as a heat pump compressor.

•  The motor protector used inside the compressors is mounted internally and its proven design is the result of
    extensive laboratory research and field testing. It protects the motor from:

           - maximum operating overload
           - high voltage
           - low voltage

•  It is both current and heat sensing. It is wired at the connection point of the motor’s three legs. Therefore, the protector
   will break all three legs. If a problem occurs with one or more of them, the protector will break all three phases (the
   single phase protector protects both the run and start windings).

•  Rated load amps. is the valve used for the contactor and other electrical component selection.
 

Evaporator Coil

PETRA'S coils are designed to deliver their duties at optimum performance for all design conditions. Coils are manufactured from seamless copper tubes mechanically expanded into aluminum fins. All coils are air pressure tested at 450 Psi, under water to avoid leakage. They also undergo dry chemical cleaning after manufacturing for optimum system cleanness. Type-L heavy wall seamless copper tubes are provided for coil headers. Evaporator coils are hydrostatic pressure tested in accordance with the UL 1995 standard.


Direct Drive Evaporator Fan

(For models: PWSP 15 - PWSP 65)

All units are provided with forward curved centrifugal fans of the Double Width Double Inlet (DWDI) type that are designed for maximum uniform air distribution. The fans are statically and dynamically balanced to ensure quiet operation and optimal performance.
 

Belt Drive Evaporator Fan

Fans are of the forward curved centrifugal Double Width Double Inlet (DWDI) type that are designed for maximum efficiency of uniform air distribution. All fans are V-belt driven with variable pitch pulley only (for fan motors with 5.5 kW and less). All fans are statically and dynamically balanced to ensure quiet operation and smooth performance.
 

STANDARD FEATURES

Construction

•  Easily accessible system components.

•  Heavy duty mounting chassis for the whole unit, coated with weatherproof, polyester powder electrostatic paint,
   oven-baked to ensure maximum gloss and hardness

•  Anti-vibration mounts under compressor (rubber pad type)

•  Compressor jacket to isolate compressor noise
 

Refrigeration

•  Expansion Device

•  Heat pump application (with suction accumulator as standard)

•  Liquid line shut-off valve (for three phase units)

•  Filter dryer (disposable for models PWSP 58 and above)

•  System is fully charged with refrigerant

•  Charging ports with charging nipples

•  Refrigerant strainer for single phase units

•  One-inlet, one-outlet water connections

•  Independent refrigeration circuits (for units with two compressors)

•  Four way valve for heat pump models
 

Electrical

•  One main power entry

•  Control circuit breaker to protect the control circuit from short circuiting (for three phase units)

•  Contactor for each motor (compressor, pump and fan motors)

•  Internal thermal protection for motors

•  ON/OFF control switch for each compressor

•  Compressor time delay relay

•  High/Low safety pressure switches

•  Power supply monitor (phase failure relay)for three phase units.
 

OPTIONAL FEATURES

Refrigeration

•  Hot gas reheat coil for humidity control

•  Liquid line moisture indicator sight glass

•  Pressure gauges (high/low gauges)

•  High pressure relief valve

•  Water regulation valve (loose item)

•  Water flow switch

•  Liquid receiver (check with PETRA factory for dimensions)
 

Electrical

•  Ground current protection for compressor

•  Building automation system connection

•  Main power circuit breaker for the whole unit with an indoor isolator

•  External overload for compressor

•  Built-in electric heater as a supplement for the heat pump application