Motors; Position Of Terminal Box; Field Wiring; Motor Protection - Grundfos CR 1s Instrucciones De Instalación Y Operación

9.1 Motors

Grundfos CR pumps are supplied with heavy-duty, 2-pole (3600
rpm), ODP (open drip-proof) or TEFC (totally enclosed fan
cooled), NEMA C frame motors selected to our rigid
specifications.
Motors with other enclosure types and for other voltages and
frequencies are available on a special-order basis.
CRN-SF pumps are supplied with an IEC (metric) type motor with
a reverse thrust bearing.
If you replace the pump, but keep a motor previously used on
another CR pump, be sure to read section
motor for proper adjustment of the coupling height.
If you install the pump outside, read section
installation.

9.2 Position of terminal box

The motor terminal box can be turned to any of four positions in
steps of 90 °.
To rotate the terminal box, remove the four bolts securing the
motor to the pump but do not remove the coupling. Turn the motor
to the desired position; replace and securely tighten the four
bolts. See fig. 11.
Outlet
Position 12:00
Position 9:00
Inlet
Fig. 11 Motor terminal box positions (top view)

9.3 Field wiring

Lead sizes should be based on the current carrying properties of
conductors required by the latest edition of the National Electrical
Code or local regulations. Direct-on-line (DOL) starting is
approved due to the extremely short run-up time of the motor and
the low moment of inertia of the pump and motor. If DOL starting
is not acceptable and reduced starting current is required, use an
auto transformer, resistance starter or soft starter. We suggest to
use a fused disconnect for each pump in case standby pumps are
installed.
14. Maintaining the
8.3 Outside
Position 3:00
Standard terminal
box position (6:00)

9.4 Motor protection

9.4.1 Single-phase motors
All CR pumps with single phase motors, except 10 HP, are
equipped with multi-voltage, squirrel cage induction motors which
include built-in thermal protection.
9.4.2 Three-phase motors
CR pumps with three-phase motors must be used with the proper
size and type of motor-protective circuit breaker to ensure the
motor is protected against damage from low voltage, phase
failure, current unbalance and overloads.
Use a properly sized circuit breaker with manual reset and
ambient-temperature compensated extra-quick trip in all three
phases. The overload protection should be set and adjusted to
the full-load current rating of the motor. Under no circumstances
should the overload protection be set to a higher value than the
full-load current shown on the motor nameplate. This will void the
warranty.
Set overload protection for auto transformers and resistance
starters in accordance with the recommendations of the
manufacturer.
Three-phase MLE motors (CRE-pumps) require only fuses as
circuit breaker. They do not require a motor-protective circuit
breaker. Check for phase unbalance (worksheet is provided. See
section 20. Worksheet for three-phase
Standard allowable phase unbalance is 5 %.
9.4.3 CRN-SF
The CRN-SF is typically operated in series with a feed pump.
Because the maximum allowable inlet pressure of the CRN-SF
increases from 73 psi (when pump is off and during start-up) to
365 psi (during operation), use a control device to start the CRN-
SF pump one second before the feed pump starts. Similarly, the
CRN-SF must stop one second after the feed pump stops. See
CRN-SF start-up timeline below.
Feed pump
CRN-SF
CRN-SF Feed pump
starts
starts
TIME starts
starts
TIME
1 or more
1 or more
Both pumps operating
Both pumps operating
seconds
seconds
Fig. 12 CRN-SF start-up
motors).
Feed pump
CRN-SF
Feed pump
CRN-SF
stops
stops
stops
stops
1 or more
1 or more
seconds
seconds
19