MA7200 PLUS Operating Manual
TECO – Westinghouse Motor Company App-2 Fan and Pump
Flow Meter monitor point Un-41 is used to display the output of the flow meter function in GPM. If the P4-01
is set to 0, the Flow Meter is zero.
Fig.1.8.1 below is a block diagram of the flow meter function when Flow Meter Selection P4-01 is set
to =1 (AUX input).
Fig. 1.8.1 Flow Meter (P4-01=1 Aux. Input)
When P4-01 is set to =1(AUX Input), the Flow Meter signal is input to terminal AUX and parameters P4-02
(Max Flow for 10V AUX) and P4-03 (AUX for No Flow) are used to set flow meter functions. Also, the
parameters below will be set automatically.
1. Parameters P4-04 and P4-05.
2. AUX Function Selection (Sn-29)
3. Terminal AUX Gain and Bias (Bn-09 and Bn-10).
These parameters can not be edited until the setting of P4-01 is changed. Also when P4-01 is set to =1 any
previous AUX Function (Sn-29) setting will become invalid.
An error message "
Flow Meter Setting Error
" will be displayed if P4-01 is set to 1 and one of the conditions
below is satisfied.
1. Sn-29 (AUX Function Selection) =9 (PID Target).
2. P1-07 (External PID Set Source) =3 (AUX Function).
3. P1-08 (External PID Feedback Source) =3 (AUX Function).
P4-02 Max Flow for 10V AUX, is used to set the maximum flow level in GPM, which corresponds to a 10 V input
to the Aux input.
Example: P4-02 is set to = 2500 GPM (max flow level).
Aux input 0 – 10 V = 0 - 2500GPM.
P4-03 Aux for No Flow, is used to offset the input signal to terminal AUX, which corresponds to
zero
flow. An
example of this would be if the input flow signal is 4-20mA, where 4mA = 0 GPM, and a 500
resistor is used
between AUX and GND. The input voltage to the AUX terminal would be 4mA x 500
= 2V. P4-03 would then
be set to =2V so that 4 mA would represent zero flow. The maximum flow would be as set in the previous
example by P4-02.
Fig.1.8.2 below is a diagram of the flow meter function while Flow Meter Selection P4-01 is set to 2 (Pulse Train
Input).
Fig. 1.8.2 Flow Meter (Pulse Train Input)
When P4-01 is set to 2 (Pulse Train Input), the Flow Meter signal is input to terminals A(+) and A(-) and the
parameters P4-04 (Pulse Multiplier) and P4-05 (Flow Meter Offset) are used to set the flow meter functions. In
this case, parameters P4-02 and P4-03 will be set automatically and can not be edited until the setting of P4-01
is changed.
Cont.