Fitting The Cable Guard; Cable Sizing; Fitting The Submersible Drop Cable - Grundfos SQ Installation And Operating Instructions Manual

4. Press the cable plug into the motor socket. The
plug cannot be fitted wrongly, see fig. 7.
Fig. 7
5. Fit and tighten the four nuts, see fig. 7.
When the plug has been fitted, there must not be a
clearance between the motor and the cable plug.

5.5 Fitting the cable guard

To fit the cable guard, proceed as follows:
1. Make sure that the submersible drop cable lies
flat in the cable guard.
2. The two flaps of the cable guard must engage
with the upper edge of the pump sleeve, see fig.
8.
Fig. 8
3. Fasten the cable guard to the cable plug with the
two screws supplied, see fig. 9.
Fig. 9
4. Fasten the cable guard to the pump suction
strainer with the two self-tapping screws sup-
plied, see fig. 10.
8
Fig. 10
Note: The cable guard must be screwed onto both
the cable plug and the suction strainer.
If the cable guard is of the flexible type, saw off the
surplus length of the cable guard.

5.6 Cable sizing

GRUNDFOS can supply submersible drop cables for
any type of installation.
Note: The cross-section of the submersible drop
cable must be large enough to meet the voltage
requirements specified in section 4.1 General .
The table values below are calculated from the fol-
lowing formula:
× × × × L ρ ×
I 2 100 PF
q
= -------------------------------------------------------------- -
× ∆U
U
where
q = Cross-section of submersible drop cable
[mm²].
I = Rated maximum current of the motor [A].
PF = 1.0.
L = Length of submersible drop cable [m].
Ò = Specific resistance: 0.02 [Ÿmm²/m].
U = Nominal voltage [V].
ƒU = Voltage drop [%] = 4%.
The 4% voltage drop is according to IEC 3-64,
HD-384 Series.
The calculation gives the following maximum cable
lengths at a supply voltage of 240 V:
Motor
I
Maximum cable length [m]
N
(P2)
1.5
[kW] [A]
mm² mm²
0.1-0.63 4.15 86 144
0.7-1.05 6.9 52
1.1-1.73 11.1 32

5.7 Fitting the submersible drop cable

It is recommended to join the submersible drop cable
and the motor cable by means of a GRUNDFOS
cable termination kit, type KM.
2.5 4 6
mm² mm²
86 138
53 86 129