08 | ENGLISH
Switch-off temperature of the sensors:
Motor
Motor
Frame
Frame
Stator Winding
Stator Winding
T1+T3
T1+T3
Regulator
Regulator
Stator
Stator
Winding FM
Winding FM
T1+T2 Limiter
T1+T2 Limiter
Lower
Lower
Bearing
Bearing
Upper
Upper
Bearing
Bearing
T
140°C / 284°F
140°C / 284°F 80°C /
176°F
n/a
P
150°C / 302°F
140°C / 284°F 80°C /
176°F
n/a
F
150°C / 302°F
140°C / 284°F 90°C /
194°F
105°C /
221°F
G
150°C / 302°F
150°C / 302°F 90°C /
194°F
105°C /
221°F
H
150°C / 302°F
150°C / 302°F 90°C /
194°F
105°C /
221°F
Seal monitoring
:
In case of a leak in the lower shaft seal, water enters
the oil chamber and changes the resistance of the oil.
The conductivity of the oil is monitored via one sensor to
ground. In the motor housing, another sensor monitors
for the resistance to ground in case of water intrusion. The
sensors are to be connected via 2 cables (consult wiring
diagram) from the pump connection cables in the control
panel to a monitor galvanically separated from the probe
circuit. The response sensitivity should be adjustable from
0-100 kΩ, the standard setting being 50 kΩ.
FM pumps: The sensors are connected via 2 cables (la-
belled S1 and S2) of the pump connector cable in the
switching system to an evaluation device with an electri-
cally isolated special circuit.
Seal monitoring for pumps with closed-loop cooling
:
The penetration of coolant (water-glycol mixture) into a
leakage chamber is registered via 2 sensors. This leakage
chamber is situated between the motor-side mechanical
seal and the bottom shaft bearing. If the motor-side shaft
bearing should leak, coolant leaks into the leakage cham-
ber and establishes the contact between both sensors.
The sensors are to be connected via 2 cables (labeled S11
and S12) from the pump connection cables in the switch
cabinet to an evaluation instrument galvanically separated
from the probe circuit.
3.3.4. Additional pump protection devices
Several optional pump protection devices are available to
protect submersible motors from damage, and may have
provided in your pump.
Temperature Sensing RTD*:
PT100 sensors are avail-
able in two critical locations on larger machines, the lower
bearings and motor windings. N.C. Circuit - 108 ohm
Moisture Sensors:
Two styles of moisture sensors are
available on HOMA pumps.
Moisture Detectors*:
These are micro float switches de-
signed to detect small amounts of liquid. These are avail-
able in the stator housing of 50hp and larger size pumps.
N.C. Circuit - 268 ohm
Leakage Detectors*:
These normally open, 2 wire probes
are used to detect the presence of water in the pump.
Optional leak detectors can be installed as follows:
• Stator Chamber installation: Probe placed in bottom
of stator housing to detect presence of water in the
chamber.
• Stator or Motor cap installation: Probe used to detect
the presence of water only into the stator housing or
motor cap terminal board.
• Closed loop cooling Installation: Probe placed in sta-
tor housing to detect the presence of liquid in the dry
chamber.
* GO switch is required for sensor operation.
3.3.5. Sealing / Seal Housing
Sealing is accomplished by two silicon carbide mechani-
cal seals in a tandem arrangement, acting independently
from each other. The seal housing is situated between the
motor and the pump housing. It consists of the bearing
housing and the pressure cover, which together form the
sealing cavity with containing white mineral oil. Monitor-
ing possibilities are available using the inspection plug on
the bearing housing and optional electronic monitoring.
3.3.6. Jacketed Pump Option
The cooling jacket has been supplied based upon the
specified operating conditions of this application. It is im-
portant this jacket is functioning properly, or the internal
motor components could become damaged. Several cool-
ing configurations are available depending upon custom-
er preference and system requirements. You must know
what configuration of cooling system is to be used with
the pump prior to installation. In some cases, field test re-
sults may indicate a change of cooling method is required.
Consult factory for necessary changes to the pump.
COOLING REQUIREMENTS
1 - Standard Media Cooled –
This construction does not require any external piping and
it is completely self-contained. This design is suitable for
the routine collection system application. No pump modi-
fications are required.
• Required Hardware – Automatic air bleed valve
mounted in upper vent port or a ¼” or 3/8” elbow and
small block valve for venting. A length of hose routed
to the sump should be attached to either air bleed or
the block valve outlet.
• Start Up Requirements – This jacket must be vented
at start up. Additional venting may be required after
situations where the suction or discharge piping has
been removed for maintenance and reinstalled. Some
adverse operating conditions can allow air to become
trapped in this jacket. This must be periodically vent-
ed off. If this occurs, it is recommended the small air
bleed valve is utilized.
2 - Media Cooled with External Flush -
This construction requires an external flow of water, typi-
cally re-use water. Applications which require this option
are typically heavy slurry or sludge service often found in
the treatment plant. This option routes the externally sup-
plied water into the pumped media. No pump modifica-
tions are required.
