Overspeed - Siemens milltronics MFA 4P Instruction Manual

5. If no response is obtained when you set the ppm potentiometer to 3 (below this
stability suffers), reset potentiometer fully CW, set switch SW2 to X 10 and then X 1
if required, and repeat step 4.
6. When Relay LED 2 goes on, indicating the incoming pulse rate, turn potentiometer
CCW slightly past this point to obtain an operating setpoint that allows for normal
fluctuations due to load and voltage variations. For 50% of full speed, set
potentiometer (and SW2 if required) to halfway between incoming pulse rate of
normal speed and 0 ppm.
7. Set Start Delay by adjusting potentiometer so that equipment being monitored can
attain normal operating speed before LED 2 can turn off.

Overspeed

1. Set switch SW3 to Overspeed.
2. Set ppm switch SW2 to X 1 position.
3. Set ppm potentiometer fully CCW to 0.
4. Determine incoming pulse rate by slowly turning ppm potentiometer CW until
Relay LED 2 goes on. Because the MFA 4p requires 2 pulses within range before
energizing relays, low ppm applications (e.g. 2 ppm) may require stepping of
potentiometer at appropriate time intervals.
5. If no response is obtained when you set the ppm potentiometer to 3, (below this
stability suffers), re-set potentiometer fully CCW and set switch SW2 to X 10, and
then X 1 if required, and repeat step 4.
6. When Relay LED 2 goes on, indicating the incoming pulse rate, turn potentiometer
CW slightly past this point to obtain an operating setpoint that allows for normal
fluctuations due to load and voltage variations.
Remember:
If N.O. contacts were shorted as described in final note of calibration
preamble, remove them now as calibration is complete.
7ML19985FM01 MFA 4p - INSTRUCTION MANUAL Page 15