P28 lube oil protection control series has a field adjustable set point and is available in both IP30 and IP66 protection class. Time delays of 50, 90 and 120 s are standard.       P45 is a low-cost lube oil protection control provided with a fixed factory set point, also to customer specifications.       P74 is designed to sense pressure differences between two points and may be used as operating or limit controls. Typical applications are to detect flow across a chiller or water cooled condenser, to detect flow in a heating system and sensing lube oil pressure differential on refrigeration compressors.