installation &
operating instructions
Design Envelope 4300 & 4380
Vertical In-line Pumping Unit
9
Layout the suction line with a continual rise towards the pump
without high points, thus eliminating possibility of air pockets
that may prevent the pump from operating eectively.
A strainer of three or four times the area of the suction pipe,
installed in the suction line, will prevent the entrance of foreign
materials into the pump. C/af" (5 mm) diameter perforations in
the strainer is typical.
In open systems, test suction line for air leaks before starting;
this becomes essential with long suction line or static lift.
Install, at the pump suction, a straight pipe of a length
equivalent to four or six times its diameter; this becomes es-
sential when handling liquids above 120°f (49°c). Armstrong
suction guides may be used in place of the straight pipe run and
in-line strainer.
Install an isolation valve in both suction and discharge lines on
flooded suction application; these valves are used primarily to
isolate the pump for inspection or repair.
Install a non-slam non-return check valve in discharge line
between pump and isolation valve to protect pump from exces-
sive back pressure and to prevent water running back through
the pump in case of driver failure on open systems.
Armstrong ftv triple function valve may be installed in place
of separate check and isolation valves. The ftv valve also
includes a throttling feature which must not be used to throttle
with variable speed pump operating in variable flow systems;
unless the pump is oversized and operating beyond the pub-
lished pump curve.
1.2.4 alignment
Design Envelope units are accurately aligned at the factory
prior to being shipped and do not need re-aligning when in-
stalled. Alignment on a Design Envelope unit may be verified by
assuring an equal and parallel gap between coupling halves on
both sides of the coupling.
2.0 electrical setup
2.1 precautions
Safety, risk of death
All electrical connections should be carried out by
a qualified and authorised electrician in accordance
with local site regulations and the latest issue of the
iee regulations.
Before removing the system must be disconnected
from the mains supply. After switching o, wait for at
least 4 minutes for the capacitors to discharge before
opening the cover.
caution
High voltage testing (Megging) of the motor/inverter
may cause damage to the electronic components and
therefore should not be carried out.
2.1.1 ground leakage current
Ground leakage current is primarily caused by the
capacitance between motor phases and the motor
frame. The Radio Frequency Interference (rfi) filter
contributes additional leakage current, as the filter circuit is
connected to ground through capacitors.
The size of the leakage current to the ground depends on the
following factors, in order of priority:
1 Switching frequency
2 Motor grounded on site or not
The leakage current is of importance to safety during handling/
operation of the Design Envelope pump if (by mistake) the on-
board inverter has not been grounded.
Since the leakage current is >3.5ma (approx. 4-20 ma),
reinforced Grounding must be established which is
required if en 50178 is to be complied with. Never use
elcb relays that are not suitable for dc fault currents (type A).
If elcb relays are used, they must be:
• Suitable for protecting equipment with a direct current con-
tent (dc) in the fault current (three-phase bridge rectifier)
• Suitable for power-up with short charging current to Ground
• Suitable for a high leakage current
2.1.2 start/stop of pump
The number of starts/stops via the mains voltage must not
exceed one-time per minute.
If a higher number of starts/stops is required, then the start/
stop digital input must be used (mains voltage directly con-
nected). This is the preferred method of starting and stopping
Design Envelope Pumps.
The three phase mains must be isolated before performing
maintenance of the pump.
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