880-ECM Series

Head Pressure Control

These electronic head pressure controls modulate condenser fan motor speed thereby varying the air volume through the condenser. The control monitors the head pressure by sensing the sub-cooled liquid line temperature or pressure.
Applications
Typically utilized on continuously variable speed condenser fan motors (ECM or VFD) in air conditioning and refrigeration systems. Use the 880-20 Model for control of one or two motor condenser applications when using up to two temperature sensors on liquid lines. The 880-25 Model adds a maximum fan speed adjustment. The 880-35 Model also includes a 24Vac heat pump mode. The 880-60 Model can control up to six motors using up to 3 temperature or 3 pressure transducers. Use the 880-90 Model for control of up to nine motors, up to three temperature sensors or three pressure sensors or a 0-10 VDC input. The 880-90 also provides serial Modbus capability if the user desires to read or set any operating parameters remotely. All models provide PWM, 0-10 VDC, and 10-0 VDC outputs for control of the variable speed fan motors.
Applicable Motors
  • ECM (brushless dc) Motors
  • Variable Frequency Drive (VFD) Motors with a 0-10 Vdc input
Features
  • Improves system performance while saving energy
  • Non-invasive sensor requires no system penetration
  • Eliminates compressor slugging
  • Sensing is independent of all refrigerant types
Typical Installations
  • Commercial A/C
  • Computer rooms
  • Hospitals
  • Grocery and convenience stores
  • Frozen food storage
  • Humidity or temperature sensitive environments
  • Cooling tower fans, glycol coolers
  • Liquid heat exchangers
880-20
  • 20mA motor drive capability modulates up to two typical ECM motors.
  • Selectable motor drive output options include adjustable 13-17Vdc peak 80Hz PWM, 0-10Vdc or 10-0Vdc (fail safe) signals.
  • Monitor one or two liquid line 10K temperature sensors with the hottest sensor controlling motor operation.
  • Adjustable LOW & HIGH sensor set points.
  • Hard start, self test, set point and motor modulation LED indicator.
  • Includes one 10K temperature sensor. Additional sensors available.
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880-25
  • 20mA motor drive capability modulates up to two typical ECM motors.
  • Selectable motor drive output options include adjustable 13-17Vdc peak 80Hz PWM, 0-10Vdc or 10-0Vdc (fail safe) signals.
  • Monitor one or two liquid line 10K temperature sensors with the hottest sensor controlling motor operation.
  • Adjustable LOW & HIGH sensor set points.
  • Adjustable 50% to 100% MAXIMUM FAN SPEED set point.
  • Hard start, self test, set point and motor modulation LED indicator.
  • Includes one 10K temperature sensor. Additional sensors available.
Stacks Image 9970
880-35
  • 20mA motor drive capability modulates up to two typical ECM motors.
  • Available 20Vdc, 15mA ECM motor “GO” SIGNAL when required.
  • Selectable motor drive output options include adjustable 13-17Vdc peak 80Hz PWM, 0-10Vdc or 10-0Vdc (fail safe) signals.
  • Monitor one or two liquid line 10K temperature sensors with the hottest sensor controlling motor operation.
  • Adjustable LOW & HIGH sensor set points.
  • 24Vdc activated selectable Direct or Reverse acting Heat Pump mode.
  • Hard start, self test, set point and motor modulation LED indicator.
  • Includes one 10K temperature sensor. Additional sensors available.
Stacks Image 9979
880-60
  • 60mA motor drive capability modulates up to six typical ECM motors.
  • Available 20Vdc, 15mA ECM motor “GO” SIGNAL when required.
  • Selectable motor drive output options include adjustable 13-17Vdc peak 80Hz PWM, 0-10Vdc or 10-0Vdc (fail safe) signals.
  • Monitor one or two liquid line 10K sensors or selectable pressure transducers with the hottest sensor or highest pressure transducer controlling motor operation.
  • Available 0-10Vdc control signal input.
  • Adjustable LOW & HIGH sensor set points.
  • Pressure input calibrated to accept P499 0.5-4.5Vdc, 750psi ratiometric pressure transducer. P499 pressure transducer market available.
  • 24Vdc activated selectable Direct or Reverse acting Heat Pump mode.
  • Hard start, self test, set point and motor modulation LED indicator.
  • Includes one 10K temperature sensor. Additional sensors available.
  • Temperature sensors and pressure transducers not included. 10K temperature sensors are available from Hoffman Controls.
  • 880-60 Product Data Sheet
  • 880-60 Installation and Operating Instructions
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880-90
  • 90mA motor drive capability modulates up to nine typical ECM motors.
  • Selectable motor drive output options include adjustable 13-17Vdc peak 80Hz PWM, 0-10Vdc or 10-0Vdc (fail safe) signals.
  • Monitor up to three liquid line 10K sensors or up to three selectable pressure transducers with the hottest sensor or highest pressure transducer controlling motor operation.
  • Available 0-10Vdc control signal input.
  • Adjustable LOW & HIGH temperature, pressure or Vdc set points.
  • Pressure input calibrated to accept 0.5-4.5Vdc, 500psi ratiometric pressure transducer. Pressure transducers are market available.
  • 24Vdc activated selectable Direct or Reverse acting Heat Pump mode.
  • Hard start, self test, set point and motor modulation LED indicator.
  • Temperature sensors and pressure transducers not included. 10K temperature sensors are available from Hoffman Controls.
  • 880-90 Product Data Sheet
  • 880-90 Installation and Operating Instructions
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Why Measure Head Pressure using Temperature instead of Pressure?

Many people assume that the best way to control the head pressure from a compressor is to directly sense the line pressure using a sensor inserted into the liquid line.