Full Product Manual

Construction
10
Grundfos COMFORT
4
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
Fig. 12 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: IP 44
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.
Fig. 13 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.
Fig. 14 Bearing pin
Rotor
The rotor is gimbal-mounted on the bearing ball with its
own step bearing.
Fig. 15 Rotor
TM05 9197 2913
TM06 52014115TM06 5202 4115TM06 5203 4115