Liberty Pumps LGV Serie Manual De Instalación página 5

Pump System Components
Control Panel
Additional Warning for Hazardous Locations
RISK OF SERIOUS INJURY OR DEATH
 Float switches must be connected to an intrinsically safe
circuit in the control panel as per the requirements of
Chapter 5 of the National Electric Code®.
All LEP-Series pumps require a separate, approved pump control
panel for operation. Operation of these models will be according
to the control selected; see separate operation instructions
supplied with the unit.
IMPORTANT: Verify the electrical specifications for the control
panel properly match those of the pump. When connecting an
LEP-Series pump to an existing control panel, verify the panel is
correctly sized and equipped for the pump.
Control and power cords shall not be spliced, although a junction
box may be used. Verify the electrical specifications for the control
panel properly match those of the pump. 3-phase models require
overload elements selected or adjusted in accordance with the
control panel instructions.
The panel must have provisions for the thermostats that open the
motor contactors. Do not exceed voltage/current combinations for
the thermostat: 24 VAC/125 VA, and 110–600 VAC/345 VA. All
models have a temperature (T) class rating of T4 (135°C) with
thermostats connected.
1-phase pumps require a motor start circuit. Liberty Pumps control
panels for 1-phase models contain the required start circuitry. If
using a non-Liberty Pumps control panel, a start circuit will need to
be installed. Table 1 contains information on the required Start Kit
and its components. A complete kit may be purchased, or the
individual components can be purchased separately using the part
numbers shown. Other options such as pre-wired kits are also
available. Consult the factory.
Table 1. 1-Phase Motor Start Kit
Component and
Specification
1-phase Start Kit
(contains all items listed
separately below)
Start Capacitor
270–324 µF 330 VAC
Run Capacitor
80 µF 370 VAC
Start Switch
Bleed Resistor, 15k Ω, 2 W
7550000F
Liberty Mfg
Pumps P/N P/N
K001864 n/a
Mars 11070 or
K001905
Equivalent
Mars 12199 or
K001902
Equivalent
Stearns SINPAC
K001903
4-7-72050-15-U03
K001904 COTS
Copyright © Liberty Pumps, Inc. 2020 All rights reserved.
For hazardous locations, the control panel must be installed
outside the hazardous area and appropriately isolated and sealed
to prevent any potential ignition or explosion. Control and power
cords shall not be spliced; a junction box may be used providing it
is rated for hazardous locations and has approved cord
connectors. Only approved controls that have intrinsically safe
float switch connections shall be used. Failure to use the proper
circuitry and to connect the thermostat will void the T4
temperature class of the pump and will drop the temperature class
to T2 (300°C).
Overload Protection
LEP-Series pumps require overload protection in the control panel.
The motor control unit shall be approved and shall be properly
sized or adjusted for the full load input power indicated on the
pump nameplate. It is important to properly adjust or select the
motor control overload protection. The full load amperes on the
nameplate should be used as a baseline, but it is important to
consider that events such as supply voltage variation or large
solids passing through the pump can temporarily increase current
draw. To avoid possible nuisance tripping, it may be necessary to
adjust overloads to a value slightly higher than the full load input
power indicated on the pump nameplate.
Thermostats
Dual seal LEP-Series motors have hermetically sealed heat sensors
(thermostats) embedded in the motor windings to detect overheat
conditions and prevent damage to the motor. The thermostats are
a normally closed (NC) switch that will open in the presence of
excessive motor temperature. The thermostats will automatically
reset when the motor has cooled to a safe temperature. The
thermostats shall be wired to interrupt power to the motor
contactor with a relay in the panel (cut power to the motor) if the
thermostats open due to motor overheating. The pump will
resume operation once the thermostats automatically reset. If
there is a need to log or monitor over-temperature events, an
external device will be needed. Tripping of the thermostats
indicates an issue that should be investigated. Liberty Pumps
control panels contain the proper circuitry to protect the motor in
the event of overheat conditions.
1-phase motors contain two thermostats and 3-phase motors
contain three thermostats, connected in series. The thermostats
are set to open at 257°F (125°C) and automatically close at 221°F
(105°C). These pumps are designed to operate under class B
thresholds with a maximum temperature of 266°F (130°C), even
though the motors are constructed with class H materials.
Power and Control Cords
RISK OF ELECTRIC SHOCK
 Do not remove cord and strain relief, and do not connect
conduit to pump.
The power and control cords are available either permanently
potted into the cord cap or field-replaceable Quick-connect cords.
For either option, the cords shall not be spliced.
IMPORTANT: Each cord has a green lead. This is the ground wire
and shall be grounded properly per NEC and/or local codes.
5 | EN