User`s manual

52
Magtrol WB/PB DynamometersChapter 2 – Installation / Mounting
2.9 POWER/HEAT DISSIPATION
All Magtrol WB/PB Series Dynamometers are instruments which absorb energy. They convert the
kinetic energy of the coupled rotating systems into heat.
The quantity of heat which can be dissipated by the dynamometers is not infinite. Additionally, the
dynamometers cannot resist excessive temperatures without damage. The most frequent consequence
of a too important energy supply is a premature deterioration of the excitation coils of the stator,
possibly inducing serious damages to the dynamometer and even to its immediate environment.
An excessive supply of energy over a long period can induce damages, which may remain undetected
if no detailed examination is performed. This can lead to a premature degradation of the bearing
lubricant, or to defects of the insulation of coils generating the magnetic field.
Converesely, dynamometers should never be loaded at full speed when cold. If a motor must be
tested cold, warm up the dynamometer with a different motor first.
Caution: it is important to familiarize yourself with the dynamometer's
ratings. running the system outside of the limits speCified in the
data sheets (see seCtion 1.2) Can Cause irreversible damage.
2.9.1 t
orque–SPeed–PoWer curVeS
The diagrams on the following pages illustrate the characteristic curves for the WB/PB Series
Dynamometers.
1 W
B 2
.7-8
(P
OW
ER
)
100
1000
10
1
100
1000
10
1
100 1000 10,000
50,000 rpm3185 rpm
100,000
Speed Limit for WB
Rotation Speed (rpm)
Torque (mN·m)
Power (W)
4
WB 2.7-8 (T
ORQUE)
3
WB 2.7-8 (T
ORQUE)
4
WB
2.7-
8 (
PO
W
ER
)
3 WB 2.7-8
(POWER)
1
WB 2.7-8 (T
ORQUE)
Figure 2–8 WB 2.7 Ratings Curve