Control Box/Panel Wiring - Grundfos SP Instrucciones De Instalación Y Funcionamiento

6.6.2 Control box/panel wiring

Single-phase motors
Single-phase motors must be connected as
indicated in the motor control box.
A typical single-phase wiring diagram using a
Grundfos control box is shown in fig. 11.
Control box
Fig. 11 Single-phase wiring diagram for Grundfos control boxes
Three-phase motors
Three-phase motors must be used with the
proper size and type of motor starter to ensure
the motor is protected against damage from low
voltage, phase failure, current imbalance and
overload current.
A properly sized starter with ambient-
compensated, class 10, extra quick-trip overload
relays or an MP204 must be used to give the
best possible motor winding protection.
Fig. 12 Three-phase wiring diagram for Grundfos motors and other motor manufacturers
12
Pressure
switch
Black
Use dotted line for
Yellow
Green
Red
Each of the three motor legs must be
protected with overloads. The thermal
overloads must trip in less than 10 seconds at
locked rotor (starting) current. A three-phase
motor wiring diagram is shown in fig. 12.
Pressure
switch
disconnect
Magnetic
starter
Green
Fused
disconnect
switch
115 V operation
Well seal
Pumps should NEVER be started to
check rotation unless the pump is
Caution
totally submerged. Severe damage
may be caused to the pump and
motor if they are run dry.
Power supply
Fused
switch
Well
seal