Homa AM***-C, Instruction Manual

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The pump must be connected electrically through a motor
starter with proper circuit breaker protection in order to
validate warranty. Do not splice cables.
10.5.4. THERMAL SWITCH WIRING
Pumps are equipped with thermal switches embedded in
the stator windings which are normally closed, automat-
ically resetting switches. Switches will open when the
internal temperature rises above the design temperature,
and will close when the temperature returns to normal.
Thermal switches must be wired to a current regulated
control circuit in accordance with the NEC.
Identify thermal switch leads marked T1 and T3 in the
power or control cable.
The resistance across the leads will be 0.5 Ohms. Ther-
mal leads must be connected to the thermal overload
relay located in the control panel. Thermal switch leads
must be connected to validate warranty.
Note: All sizes of Class 1, Div. 1 pumps for hazardous
service must have thermal switch leads connected to
a current regulated control circuit in accordance with
NEC.
10.5.5. SEAL PROBE WIRING
The mechanical seal leak detector probe utilized in the
pump is a conductive probe which is normally open. The
intrusion of water into the seal chamber completes the
electrical circuit. Control panel provisions will sense this
circuit closure, and will provide indication or alarm func-
tions depending on the panel design. Either single or dual
wire systems may be provided. Single wire systems uti-
lize one energizing conductor, and the pump casing and
neutral lead as the ground or return portion of the circuit.
The dual wire systems utilize two separate conductors for
each leg of the circuit.
With either system, the seal probe leads must be wired
into a control circuit provided in the control panel. This
control circuit must energize the probe with a regulated
power source, and sense the closed circuit in event of
water intrusion Indication and alarm functions must also
be provided in the control circuit. Please see control panel
wiring diagram for seal probe connection points.
For Hazardous Area Classification Pumps, leak de-
tector circuit must be in conformance with applica-
ble NEC codes and regulations.
10.5.6. START / RUN CAPACITORS AND RELAYS:
All single phase motors require start and run capacitors
along with a start relay to operate. Capacitors and relays
must be sized for the specific motor.
Capacitors are sized based on ideal conditions.
The run capacitor may need to be resized to match the
available field voltage. Each cap kit shipped is supplied
with a wiring diagram and start up procedure.
10.5.7. Variable Frequency Drives
Special considerations must be taken when operating
pumps with variable frequency drives (inverters).
The
inverter circuit design, horsepower required by pump, mo-
tor cooling system, power cable length, operating voltage,
and anticipated turndown ratio must be fully evaluated
during the design stage of the installation.
As a minimum, properly sized load reactors and filters
must be installed between the inverter and the pump
to protect the pump motor from damaging voltage
spikes.
Warranty coverage will not be provided on any pump mo-
tor that is operated with a variable frequency drive, unless
the load side of the inverter is properly isolated from the
pump.
10.6. ADDITIONAL PUMP PROTECTIVE 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 available 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, single or 2
wire probes are used to detect the presence of water in
the pump. Single wire probes use the pump ground to
complete circuit. 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.
* relay is required for sensor operation.
10.7. MECHANICAL INSTALLATION
10.7.1. PUMPS WITH AUTOCOUPLING SYSTEMS
The HOMA Auto-Coupling is a quick removal system used
in keeping personnel from having to enter the wet well.
The pump mounts on a stationary base and operates com-
pletely or partially submerged (minimum 10” over volute)
in the pumping media.