Specification

4. Construction
Grundfos COMFORT PM circulator pumps are available in
various pump housing versions and lengths incorporating
isolating and non-return valves or prepared for
subsequent fitting of such valves.
The motor can be separated from the pump housing,
enabling easy maintenance and replacement.
The rotor bearing is self-adjusting and lubricated by the
pumped liquid.
The pumps have the following characteristics:
• Parts in contact with the pumped liquid are
hermetically separated from the stator by a stainless-
steel spherical separator.
• The bearing has no play, and as it has only a single
bearing point, it generates very low friction, resulting in
reduced power input and noise.
Electrical insulation
TM059197
Protection Class II symbol
All Grundfos COMFORT PM models are electrically
double insulated (Protection Class II). This makes the
protective earth connector obsolete.
Motor
The motor is a single-phase, 12-pole, permanent-magnet
motor in conformity with the EMC directive.
The permanent-magnet motor has no rotating bearing
shaft. A green indicator light on the motor is on when the
motor is running.
The pump motor is impedance-protected and short-circuit-
proof. No additional motor protection is required.
The terminal box is easily accessible and has functional
cable connecting terminals. The cable entry is tight and
incorporates cable relief.
Enclosure class: IP44
Insulation class: F.
Voltages
• Europe: 1 x 230 V, 50/60 Hz
• UK: 1 x 230 V, 50/60 Hz
• China: 1 x 230 V, 50/60 Hz
• USA: 1 x 115/230 V, 50/60 Hz.
Stator
The stator generates a magnetic field acting directly on
the magnetic rotor. As a result, the rotor is caused to
rotate. The axial components of the magnetic field act as
an attractive force on the rotor, thus stabilising it in its
longitudinal axis.
Spherical separator
The stainless-steel spherical separator hermetically seals
the water-conducting part of the pump from the electrically
active part of the motor without any additional seal.
TM065201
Spherical separator
Bearing pin and bearing ball
The stainless-steel bearing pin is homogeneously welded
by laser beam to the spherical separator and the bearing
ball.
TM065202
Bearing pin
Rotor
The rotor is gimbal-mounted on the bearing ball with its
own step bearing.
TM065203
Rotor
COMFORT
4
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Construction