Column pipe installation, type ST
Pos.
Description
a
Minimum water level for operation
72 and 74: 35.4 in (900 mm)
b
78: 43.3 in (1100 mm)
c
All: 15.7 in (400 mm)
6. Electrical connection
DANGER
Electric shock
Death or serious personal injury
‐
Before starting any work on the product, make sure
that the power supply is switched off and that it cannot
be switched on unintentionally.
Connect the pump to an external main switch ensuring all-pole
disconnection with a contact separation according to National
Electrical Code (NEC) and all local codes. It must be possible to
lock the main switch in position 0.
The supply voltage and frequency are marked on the nameplate.
Make sure that the motor is suitable for the power supply available
at the installation site.
Carry out the electrical connection in accordance with
local regulations.
The pump must be connected to a motor-protective circuit breaker.
Connect the pumps to a control box with a motor
protection relay with an IEC trip class 10 or 15.
Connect the pumps installed in hazardous locations to a
control box with a motor protection relay with an IEC trip
class 10.
For Ex models in dry-installation, version D and H,
FM
connect an external grounding.
The motor is effectively earthed through the earth conductor of the
power cables and the pipes. The motor top cover for Ex pumps is
equipped with connections for external earthing or an equipotential
bonding conductor.
6.1 Wiring diagrams
Standard power cables
a
W1
U1
V1
W2
U2
V2
Wiring diagram for standard power cable
The wiring diagrams in custom-built products may differ
from the standard. In this case, contact the nearest
Grundfos company or an authorized workshop.
1
U1
U2
U1
U1
2
U2
U2
3
V1
V2
V1
V1
4
V2
V2
5
W1
W2
W1
W1
6
W2
W2
17