861-ASQ
Condenser Fan Sequencer
The 861-ASQ Series Sequencer is a direct-acting electronic step controller used to control multiple condenser fan motors in incremental, sequential steps for low ambient control of air-cooled condensers.
Features
- Liquid line sensing
 - Multiple input/output functions
 - Adjustable staging
 - LED stage indicators
 - Momentary loss of power protected
 - Accepts input from 851-MS Multi-Sensor Selector
 - Output for 816-DH(DC) Head Pressure Controller
 
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. 
