15
Installation, Operations & Maintenance Manual
SECTION 3 - OPERATION
4. Disconnect ECC from pump. Remove the four
screws that mount the ECC to the bracket
and carefully remove the ECC from the pump.
On MAXROY
®
B pumps loosen coupling nut
(
Figure 19
, Item 865) and coupling (860) to allow
free rotation of ECC shaft.
5. Apply power to ECC and allow it to run to its
new position at a zero mA signal. Ensure the
capacity control knob did not rotate.
6. Apply a 4 mA signal to place ECC in reverse
acting mode. This is now the 100% capacity
setting.
7. With ECC and pump capacity knob at 100%
capacity setting, carefully slide the ECC shaft
back into the coupling and replace the four
mounting screws. If required, rotate the pump
adjustment screw to allow assembly. Do not
move the ECC shaft. On MAXROY
®
B pumps
tighten coupling nut (
Figure 19
, Item 865)
and coupling (860) (Approximately 40 lb. ft.).
Pin should remain in approximate midpoint of
slot in coupling.
8. Check operation through full signal range and
recalibrate if required (See ECC Calibration,
Section 4).
3.2.2 Input Signal
The ECC is shipped from the factory adjusted to
accept a 4-20 mA command signal. If the unit is to
be operated with any other range, it must be set
up for that range.
• Adjusting the span control, VR1,
Figure 11
,
determines the maximum travel of the ECC over
the full range of the command signal.
• Adjusting the zero control, VR2,
Figure 11
shifts
the position of this travel
(Figure 9)
.
The ECC may be set up to operate over
a “split range” of either 0 to 100% capacity
corresponding to a 12 to 20 mA signal, or 0 to
100% capacity corresponding to a 12 to 4 mA signal
(in reverse action mode) - such as pumps A & B in
a typical pH control system, shown in
Figure 10
.
5
1
0
100
Pump Capacity %
Monitor Voltage
Command Signal mA
20
4
Zero Adjust
Span Adjust
Figure 10. Effect of Zero & Span Controls
Figure 11. Split Range Operation with Two
Pumps (Typical pH Control System).
20
12
4
0
100
0
7
14
Pump Capacity %
Reverse Acting
Pump B
Direct Acting
Pump A
Command Signal mA
pH
