24V Single Point Level Control Sensor for Ammonia

These compact single point level sensors and switches are economical solutions for reliable and accurate level detection. They are designed to detect the presence of liquid (but not oil) at a specific location in vessels containing refrigerant. The computer-compatible, low-voltage signal output of the level sensor can be used directly with plant computers, PLCs, solid-state relays or other controllers. The relay output from the level switch is suitable for direct connection to solenoids, alarms, and computers.

More compact than mechanical float devices, these level devices are very reliable, even in low- temperature systems. Unlike optic devices, they are not affected by film buildup or oil scum. Also, there is no lens to be fooled by frost buildup. They come factory pre-calibrated and tested; ready to use. There are no moving parts in the probe to break, jam, or fail.

Electronics can be easily replaced without pumping out (opening) the system. The NPN level sensors are low-voltage, three-wire devices which have NPN (current sinking) output. The control loop wire size should be at least 20 AWG (0.5 mm2) and limited to 100 ft. (30 m). For best electrical noise protection, use shielded cable, and do not run control loop wiring with or near power wiring.

A small, bright LED inside sensor housing illuminates to indicate the presence of liquid. With liquid at the probe, the output signal will be 15% of the voltage supply (LED on). In the absence of liquid at probe, the output signal will be 90% of the voltage supply (LED off). This is a Single point Level Control sensor for use in ammonia refrigeration systems only, with a capacity of 24V and with a standard connection of 1/2" MPT.