Grundfos UPML, Installation And Operating Instructions Manual

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9
English (US)
Inrush current
The inrush current is the charge current to the electrolytic
capacitor in the power supply to the electronics. The maximum
current amplitude depends on the power supply and the complete
wiring from the distributor transformer to the pump. The pump is
internally controlled by a small frequency converter running on a
DC voltage. Therefore, the supply voltage is rectified to a DC
voltage before it reaches the frequency converter. This is done by
a rectifier and a capacitor.
Fig. 6 Rectification of VAC voltage to DC voltage
The load of electronically commutated motors (ECM) behaves as
a capacitive load and not as a motor load like in a standard pump.
When the power supply is switched on, the capacitor will behave
as a short-circuit (as it is "empty", i.e. it has not been charged).
Therefore, the current is only limited by the sum of the resistance
in the NTC thermistor and the resistance in the coil of the EMC
filter.
If the power supply is switched on when the supply voltage is at
its highest level, the inrush current can become very high for a
very short period of time. After this period of time, the current will
drop to the rated current.
When the power supply to the pump is switched on and off via an
external relay, it must be ensured that the contact material of the
relay is able to handle higher inrush currents. We recommend to
use special inrush relays with silver tin oxide (AgSnO) contacts
Leakage current
The pump mains filter causes a leakage current to ground during
operation.
High-voltage test
The pump incorporates filter components that are connected to
ground. The voltage level and the number of tests should be as
low as possible, in order to grant the longest lifetime in the
market. Additional standard high-voltage tests of the complete
pump including filter should be avoided to eliminate the risk of
filter damage.
Ground fault circuit interrupter (GFCI)
If the pump is connected to an electrical installation where a
ground fault circuit interrupter (GFCI) is used for additional
protection, this Ground Fault Circuit Interrupter shall be able to
trip when ground fault currents with DC content occur.
Fig. 7 GFCI connection diagram
5.5.1 Power supply connection
TM0
5
1
1
57
23
11
WARNING
Electric shock
Death or serious personal injury
- Use a suitable type of GFCI capable of handling
ground fault currents with DC content (pulsating
DC).
EMC filter
NTC
thermistor
Rectifier
Capacitor
DC voltage to
the frequency
converter
T
M
07
05
40
02
18
DANGER
Electric shock
Death or serious personal injury
- All electrical work must be carried out by a
qualified electrician in accordance with the latest
edition of the National Electric Code and state,
local codes and regulations.
DANGER
Electric shock
Death or serious personal injury
- Switch off the power supply before starting any
work on the product. Make sure that the power
supply cannot accidentally switched on.
WARNING
Electric shock
Death or serious personal injury
- This pump is supplied with a grounding conductor.
To reduce the risk of electric shock, be certain that
it is connected only to a properly grounded,
grounding-type receptacle in accordance with the
National Electric Code and any state, local
governing codes and regulations.
WARNING
Electric shock
Death or serious personal injury
- The connection to the fixed wiring systems must
be made using a flexible conduit system only.
- The terminal block is suitable for copper
conductors only.
Do not use the pump with an external speed control
which varies the supply voltage, for example phase-
cut or pulse-cascade control.
Do not connect the pump using rigid conduit
connections.
Check that the supply voltage and frequency
correspond to the values stated on the pump.
All cables and connectors used must be connected in
accordance with local regulations.
L
N
L
N
GFCI
External switch
Fuse
UPMM_UPML_UPMXL_US.book Page 9 Tuesday, February 26, 2019 10:18 PM