Greystone UPB1BX Ultra-Low Pressure Transmitter, BACnet MS/TP, 1 in WC / 250 Pa, No Relay, Polycarbonate

Greystone UPB1BX is an ultra-low differential pressure transmitter for dry air or clean inert gas, with a backlit LCD. This BACnet model's selectable pressure magnitude is 1 in WC or 250 Pa, configurable for 0 to full-scale or bidirectional +/-full-scale operation. The B output option provides two-wire RS-485 BACnet MS/TP communications, with baud rates of 9600, 19200, 38400 or 76800 and a locally set MAC address from 0 to 127 (factory default 3). The manufacturer shows separate BACnet and analog PCB configurations; this model is described by its BACnet communications option, not by the analog-output list.

The B enclosure option is grey polycarbonate with a hinged, gasketed cover, rated IP65 and NEMA 4X. Mount using the base mounting holes. The transmitter can be mounted in any position; typical installation is on a vertical surface with the pressure ports and cable entrance at the bottom. Avoid severe vibration, excessive moisture and kinked pressure tubing.

The X option specifies no relay. Response time is selectable from 1-60 seconds through the local menu or BACnet. Auto-zero is available by pushbutton or BACnet communication. The LCD displays pressure in in WC or Pa, with enable, disable or automatic backlight settings.

Accuracy is +/-1% full scale of the selected range at 22 C (72 F), including hysteresis, non-linearity and repeatability. Power input is 24 Vac/Vdc, +/-10%, with a maximum specified consumption of 52 mA. Operating conditions are 0-50 C (32-122 F) and 0-95% RH, non-condensing. The device includes reverse-voltage protection and output-limited protection circuitry.

Screw terminals accept 14-22 AWG wiring. Pressure connections use 6.35 mm (1/4 in) nylon barb fittings for 3.175-4.762 mm (1/8-3/16 in) inside-diameter tubing. The enclosure provides an opening for 1/2 in NPT conduit or a suitable cable gland. Follow the manufacturer installation and model-specific wiring instructions.