Bard GVDM-26, Installation Instructions Manual, Page: 10 / 11

Manual 2100-517
Page
10 of 11
CONTROL BOARD SEQUENCE of
OPERATION
The desuperheating control board will make a determination
whether or not to energize the pump relay inclusive on the
control board.
A. It will constantly monitor inputs from two temperature
sensors, Inlet & Outlet water sensors.
B. It will constantly monitor the Y signal.
C. Upon acknowledgment of Y signal, and following two
minutes, the control board will energize the pump relay.
D. After 1½ minutes, based on temperature difference
between Outlet & Inlet sensors, and the presence of Y
signal, the following will take place:
F R F R
0 . 3 5
0 . 2 5
0 . 3 5
0 . 4 5
0 . 5 5
0 . 6 5
0 . 7 5
0 . 8 5
0 . 9 5
0 . 0 6
0 . 1 6
0 . 2 6
0 . 3 6
0 . 4 6
0 . 5 6
0 . 6 6
0 . 7 6
0 . 8 6
0 . 9 6
0 . 0 7
0 . 1 7
0 . 2 7
0 . 3 7
0 . 4 7
0 . 5 7
0 . 6 7
0 . 7 7
0 . 8 7
0 . 9 7
0 . 0 8
0 . 1 8
0 . 2 8
0 . 3 8
0 . 4 8
0 . 5 8
0 . 6 8
0 . 7 8
0 . 8 8
4 7 3 9 1
7 6 8 8 1
5 7 3 8 1
9 8 9 7 1
4 3 4 7 1
4 8 9 6 1
7 4 5 6 1
2 2 1 6 1
0 1 7 5 1
0 1 3 5 1
1 2 9 4 1
4 4 5 4 1
7 7 1 4 1
0 2 8 3 1
4 7 4 3 1
7 3 1 3 1
0 1 8 2 1
2 9 4 2 1
3 8 1 2 1
3 8 8 1 1
1 9 5 1 1
7 0 3 1 1
1 3 0 1 1
2 6 7 0 1
1 0 5 0 1
7 4 2 0 1
0 0 0 0 1
0 6 7 9
6 2 5 9
9 9 2 9
7 7 0 9
2 6 8 8
3 5 6 8
9 4 4 8
0 5 2 8
7 5 0 8
9 6 8 7
6 8 6 7
0 . 9 8
0 . 0 9
0 . 1 9
0 . 2 9
0 . 3 9
0 . 4 9
0 . 5 9
0 . 6 9
0 . 7 9
0 . 8 9
0 . 9 9
0 . 0 0 1
0 . 1 0 1
0 . 2 0 1
0 . 3 0 1
0 . 4 0 1
0 . 5 0 1
0 . 6 0 1
0 . 7 0 1
0 . 8 0 1
0 . 9 0 1
0 . 0 1 1
0 . 1 1 1
0 . 2 1 1
0 . 3 1 1
0 . 4 1 1
0 . 5 1 1
0 . 6 1 1
0 . 7 1 1
0 . 8 1 1
0 . 9 1 1
0 . 0 2 1
0 . 1 2 1
0 . 2 2 1
0 . 3 2 1
0 . 4 2 1
7 0 5 7
4 3 3 7
5 6 1 7
0 0 0 7
0 4 8 6
3 8 6 6
1 3 5 6
3 8 3 6
9 3 2 6
8 9 0 6
1 6 9 5
7 2 8 5
7 9 6 5
0 7 5 5
6 4 4 5
6 2 3 5
8 0 2 5
4 9 0 5
2 8 9 4
3 7 8 4
7 6 7 4
3 6 6 4
2 6 5 4
4 6 4 4
7 6 3 4
4 7 2 4
2 8 1 4
3 9 0 4
6 0 0 4
1 2 9 3
8 3 8 3
7 5 7 3
8 7 6 3
1 0 6 3
6 2 5 3
2 5 4 3
TEMPERATURE F vs RESISTANCE R OF TEMPERATURE SENSOR
1.) If temperature difference is greater than 3°F, then
the control will continue to energize pump relay.
2.) If temperature difference is less than 3°F, then the
control will de-energize the pump relay.
3.) The control will next wait for 10 minutes before
repeating Step #1 (above).
E. The Over Temperature Limit Switch is placed in series
with the line voltage. Therefore, continuity between L
of line voltage and L of pump output is forced broken
when the Over Temperature Limit Switch opens (see
Wiring Diagram).
F. The 3-amp fuse is put in series with the R connection to
the board. Whenever the fuse is blown, the control will
lose power and consequently, the relay will disengage.
Figure 5
THERMISTOR