Series P74 measures the pressure difference between two sources: supply lines and return lines. A change in differential pressure will reposition the switching mechanism to cause corrective action of the supplementary control equipment.
Features
• field-proven Pennswitch with a completely enclosed contact mechanism
• pressure differential setting is easily changed without removing the cover
Applications
• differential pressure sensing on chillers or water-cooled condensers
• lube oil failure cutout for refrigeration compressors (same as the P28, but does not incorporate time delay)
• positioning M100 Series motor-actuated valves (P74JA-2)
• to prove pump operation
