IMP Pumps NMT(D) 40-100 & NMT SAN flanges - Manual (Page 18)

GB
-18-
3.1.1 d
ifferential pressure regulatiOn
(∆
p
)
Fig. 1
Unregulated pump decreases head with increasing flow (Fig. 1, curve a). Typical system with
thermostatic valves increases the head when the valves are closed and hot water flow is not
needed. Electronic regulation can provide constant head by modifying power input (Fig. 1,
curve b). Additional energy savings and noise reduction are achieved with proportional head
regulation that also compensates for pressure drop in the pipes (Fig. 1, curve c). Pump is factory
set to operate in this mode. »Qprop« factor provides user adjustable curve slope. Qprop of 0%
means that the head does not exhibit any dependence to flow. Qprop set to 60% means that the
pressure will drop for 60% from set value when there is no flow. For example if the head is set
to 5m, the pump will only provide 2m when the valves are closed.
Substantial percentage of glycol in the mixture can influence regulation.
3.1.2 rpm
regulatiOn
Provide regulation similar to manually adjustable pump.
3.1.3 p
Ower limitatiOn
Artificially limit power consumption and output.
3.2 e
lecTrical connecTions
Connection box layout:
Fig. 2