Relay Output The BW100 offers one single pole double throw (SPDT) relay that can be assigned (P100) to one of the following alarm functions: Operation • rate: relay alarms on high and/or low material flow rate. • auto zero: relay alarms when an attempted auto zero calibration reports an out of range condition (E9). • speed: relay alarms on high and/or low belt speed. • load: relay alarms on high and or low belt load. • error: relay alarms on any error condition as it is reported. • Refer to Troubleshooting, page 65. Except for alarm on ‘auto zero’ and ‘error’, the high and low alarm setpoints (P101 and P102 respectively) are required and must be entered in the appropriate units.
The on / off actuation at both setpoints is buffered by the damping (P080) and the programmable dead band (P117), to prevent relay chatter due to fluctuations. The relay is normally energized; i.e. the normally closed (n.c.) contact held open. Upon an alarm condition, the relay is de-energized and the alarm icon on the BW100 display appears. Once in alarm, the relay and icon remain in alarm status until the alarm condition is removed. Example: P014 = 2m/s, design speed P100 = 3, belt speed P101 = 100% (2m/s) high 100% 2 m/s low 20% actual OFF 22% actual ON 20% 2% 0.4 m/s alarm ON is with relay de-energized Page 44 Milltronics BW100 - INSTRUCTION MANUAL 7ML19985DJ01