the "/U" suffix simply denotes the retail-packaged universal version of the same Honeywell ignition cable

This relay operates on a 24VAC control circuit

ensuring the BACnet or Analog controller receives a clean

and Series 3-CT versions

Designed to withstand the demanding pressures of industrial process steam

Schneider Electric (Barber Colman) 2378-501 Relay Els PW 17895 the "/U" suffix simply denotesThe Schneider Electric (Barber Colman) 2378 501 Relay is a high performance pneumatic amplifying relay designed for proportional signal control in HVAC systems. Engineered as a Pneumodular component, this device provides a definitive 2: 1 amplifying function, doubling the input signal pressure to the branch line. This is essential for contractors managing larger actuators or terminal units that require higher pressure than the standard controller