How It Works - Pentair PENTEK PPC7 Série Manuel D'installation

Installation

HOW IT WORKs

This Variable Frequency Drive (VFD) provides constant
water pressure under varying service conditions in pumping
applications. It drives a standard pump according to
pressure needs received from an accurate transducer. Motor
speed varies to deliver constant water pressure (within the
limits of the pump) despite variations in water demand and
flow.
When the system flow demand is light, the pump runs
at a relatively low speed. As system demand increases,
the motor speed increases to maintain the preset system
pressure.
In general, when there is a demand for water, the Control
will be operating. However, with light demand, the pump
may cycle on and off at its minimum speed. This will not
damage either the motor or the pressure transducer.
INsTaLLaTION FOR submERsIbLE
PumP aPPLICaTIONs
Install the Transducer
1. Disconnect the electrical power at the main circuit
breaker.
2. If there is water in the system, drain it.
NOTE: Before connecting the pump to the system, 'pump out' the well to clean it. Be sure that the transducer
is connected to the VFD and sees 0 PSI pressure. Throttle the pump discharge to reduce the load on the motor.
Once the well is clean, proceed with plumbing the well.
Figure 1: General Layout. NOTE: For Models rated NEMA 3R, all wiring to the VFD must be in liquid tight conduit
with liquid tight connectors to maintain the box's NEMA rating.
(See Figure 1)
3. The system requires a pressure tank; for best pressure
regulation, use a 6 gallon tank or larger. You can also
use an existing tank of much larger capacity. Set the
tank pre-charge at 70% of the set-point pressure (42 psi
when the Control is set at 60 psi – see Table 3, Page 7).
4. Install the pressure transducer in a tank tee or in a tee in
the water main downstream from the tank and less than
10 feet from it. Do not install any elbows between the
tank and the pressure transducer. The VFD includes a
10 foot length of cable to connect the transducer to the
VFD.
NOTE: If you have a pressure gauge in the system,
make sure that the gauge and the transducer are on
the same level. If the gauge is higher or lower than
the transducer, the gauge pressure will not match the
transducer's signal. The VFD will, of course, always be
governed by the transducer's signal.
NOTE: The pressure transducer is pre-calibrated; no
adjustment is needed.
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