Electrical Connection; Maintenance; Installation - Grundfos LC-Ex4 Installation And Operating Instructions Manual

4. Electrical connection

The electrical connection must be carried out in
accordance with local regulations and special local
Ex regulations, if any.
Warning
Install the unit outside the potentially
explosive area.
Warning
As the LC-Ex4 and FB-Ex4 have a
safety barrier without galvanic
separation, an earth connection is
necessary for safety reasons.
4.1 Electrical data
Um 250 V
Uo 16.9 V
Co 305 nF
Max. Lo/Ro ratio
The LC-Ex4 unit has two cables which must be
connected to the LC 108 or LCD 108 controller
inputs for float switches.
The float switches must be connected to the inputs
of the LC-Ex4, see the wiring diagram in fig. B,
page 16.
When connecting the float switches, note whether
the float switch should close or open the contact to
start the pump.
See also section "Electrical connection" in the
installation and operating instructions for the LC 108
or LCD 108 controller.
See also the mounting sketch in fig. A, page 15, and
the wiring diagram in fig. C, page 17.
The unit must not be exposed to direct
Caution
sunlight.

4.2 Installation

Intrinsically safe wiring must be installed in
accordance with the requirements of EN 60079-14
(Explosive atmospheres - Part 14: Electrical
installations design, selection and erection).
Place the LC-Ex4 in vertical position. See fig. A,
page 15.
Make sure that the cable diameter and cable gland
match.
The cable glands of the earth cable: Pg 7, cable
diameter of ∅3 to ∅6.5.
The cable glands of the float switches: Pg 9, cable
diameter of ∅4 to ∅8.
The cable sheath must be intact all way
through the cable gland and minimum
20 mm inside the box.
Note
Do not strip more conductor insulation
and cable sheath than required to fit
the terminals inside the box.
6
Po 0.4 W
Io 94 mA
Lo 1 mH
71 μH/Ohm

5. Maintenance

Under normal operating conditions, the unit is
maintenance-free, see section 6. Fault finding chart.
Warning
Make sure that no work is carried out in
potentially explosive environment.
Warning
Before starting work on the product,
switch off the power supply. Make sure
that the power supply cannot be
accidentally switched on.
5.1 Replacement of parts
The Zener barrier unit or the box including the Zener
barrier unit can be replaced.
The Zener barrier unit must not be
Note
repaired.
5.2 Product numbers
Unit
FB-Ex4, Zener barrier unit
LC-Ex4, box including the
Zener barrier unit
Product number
96538241
96440300