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6. Electrical Connection
Before operation, an expert check must secure that
the required electrical protection measures exist. The
connection to ground, earthing, isolating transformer, fault
current breaker or fault voltags circuit must correspond to
the guidelines set forth by the responsible power plant.
The voltage required in the technical data sheet
must correspond to the existing line voltage.
Submersible pumps used outside of buildings must
have a cable with a minimum length of 10m.
Make sure that the electrical pin-and-socket connec-
tions are installed flood- and moisture-safe. Before start-
ing operation check the cable and the plug against dam-
ages.
The end of the pump power supply cable must not be
submerged in order to prevent water from penetrating
through the cable into the motor.
The normal separate motor starter/control box of
standard as well as of explosion proof pumps must
not be installed in explosive enviroments.
6.1. Connection of 1 Ph-Motors
TP 28 and TP 30 pumps with 1Ph-motors are supplied
with or must be connected to a seperate control box with
motor starter and operating capacitor. If any other than an
original HOMA control unit is used, make sure that the
thermal relay in the motor starter is set according to the
nominal current consumption of the pump motor (see
data on pump label). For capacitor sizes, see table below:
Pump type
Operating capacitor
µ
F
V
AC
TP 28
25
450
TP 30 up to 0,9 kW (P
2
)
25
450
TP 30 above 1,0 kW (P
2
)
30
450
6.2. Connection of 3 Ph-Motors
TP 28 and TP 30 pumps with 3Ph-motors are supplied
with or must be connected to a separate control box with
motor starter, available from the HOMA accessory pro-
gram. If any other than an original control unit is used,
make sure that the thermal relay in the motor starter is set
according to the nominal current consumption of the
pump motor (see data on pump label).
Motor-Start
The motors of pump types TP 28 and TP 30 are designed
for direct-on-line (DOL) start. All motors with 400 V volt-
age indication on the pump label have their motor wind-
ings internally star-connected for operation at 400 V / 3Ph
power supply. The motor cable wires indicated U, V. W
must be connected to the power supply wires indicated
L
1
, L
2
, L
3
through the motor starter according to page 21.
6.3. Temperature Sensors
The explosion proof models of TP 30 pumps have a set of
temperature sensore built in the stator windings. The con-
tact of these sensors opens in case of overtemperature
and switches off the motor power supply. Standard mod-
els of TP pumps with temperature sensors are available
upon request.
Standard models of 1Ph-motors have the sensors (built in
upon request) internally connected, so that no external
connection to the control box is necessary. When the mo-
tor cools, it is switched on again automatically.
Standard models of all 3Ph-motors have the sensors
(built in upon request) connected to the motor power sup-
ply cable, the wire ends marked T
1
and T
3
. They must be
connected to the safety circuit of the control box in order
to provide an automatic re-start of the motor, when the
motors cools. The switch-off temperature of the sensors
for standard models is approx. 130°C.
Explosion proof models (1 Ph and 3 Ph) have a set of
lock-out-device ends temperature sensors with a higher
switch-off temperature of approx. 140°C, connected to the
motor cable, the wires are marked T
1
and T
2
. They must
be connected to the safety circuit of the control box in or-
der to provide a manual re-start, when the motor cools.
This can be done by switch-off the mains power supply
and switch on again after approx. 5 minutes.
6.4. Check of Direction of Rotation
1 Ph-pumps do not require any check, as they always run
with the correct direction of rotation.
3 Ph-pumps must be checked for correct direction of rota-
tion before start-up. On original HOMA control boxes a
control-light is illuminated, if the direction of rotation is not
correct.
With smaller pumps the direction of rotation may be che-
cked by watching the start-jerk. Put the pump vertical on
the ground and lift one edge. Start the motor. Viewed
from above, the unit must jerk anti-clockwise, as the cor-
rect direction of rotation is clockwise. With bigger pumps
the check may also be done by watching the rotation of
the impeller through the discharge or the suction inlet.
With pumps already installed, the check may be done by
comparing head (pump pressure) and flow (quantity of
water) at different direction of rotation. The direction that
gives higher head and flow is the correct one.
If the direction of rotation is wrong, interchange two of the
phases of the electric power supply. Using an original
HOMA control box with CEE-plug, this may be done by a
180° turning of the small round pole-socket at the plug-
end with a screwdriver.
7. Installation
Pay attention to the maximum depth of immersion
(see pump label).
If the pump is installed in a sump, the sump opening
must be covered with a tread-safe cover after installation.
The operator has to prevent damage through the
flooding of rooms caused by defects of the pump through
the use of appropriate measures (e.g. installation of alarm
units, backup pump or like that).
7.1. Submerged Base Stand Installation
Fix a 90° elbow to the pump discharge. The pump may be
installed with a flexible discharge hose or a rigid pipe,
non-return valve and isolating valve. If a flexible hose is
used, make sure that it does not buckle.
Fix a rope or a chain to the pump handle and lower the
pump into the liquid. If the pump is installed on muddy
ground, support it on bricks to prevent it from sinking in.
