
22
Magtrol WB/PB Dynamometers
Chapter 1 – Introduction
6
MAGTROL
tanDeM DYnaMoMeter ratings
Tandem Specifications
* Voltage at 20 °C is 30 volts.
Because the characteristics of the WB and PB Dynamometers
are complementary, Magtrol is able to offer them mounted
in a tandem setup. Each dynamometer (WB and PB) can
autonomously operate according to its own characteristics.
An electromagnetic clutch is needed for this application
which automatically switches off at the maximum speed of
the PB Powder Dynamometer and automatically switches on
at zero speed.
tanDeM operating principles
tanDeM torque–speeD–poWer curves
The diagram below shows the characteristic curves for the 65 Series Tandem Dynamometers.
Speed Limit f
or
Tandem 65
Rotation Speed (rpm)
To
rque (N·m)
Po
wer (kW
)
2 WB 65 + EK + 2 PB 65
(TORQUE)
2 WB 65 + EK + 1 PB 65
(TORQUE)
2 W
B
65
+
E
K
+
2 P
B
65
(P
OW
ER
)
2 W
B 6
5 +
EK
+
1 P
B 6
5
(P
OW
ER
)
100
10
1
100
10
1
100
1000
10,000
18,000 rpm
570 rpm
5730 rpm
100,000
Optical Speed Sensor
Each 65 Series Tandem Dynamometer has an optical speed
sensor with a 60-bit pulse wheel delivered as standard.
Cooling Water Consumption
For all Tandem models:
≈
30 l/kWh at
∆
t
= 30 °C (Metric)
≈
8 gal/kWh at
∆
t
= 86 °F (US)
Model
Rated Torque
Drag Torque
De-energized
Nominal Input Inertia
Rated
Power
Rated
Speed
Max.
Speed
Excitation
Current*
N·m
lb·ft
N·m
lb·ft
kg·m²
lb·ft·s²
kW
rpm
rpm
A
2 WB 65 + EK + 1 PB 65
25
18.4
0.7
6.19 3.19 × 10
-3
2.35 × 10
-3
12
5730
18,000
5
2 WB 65 + EK + 2 PB 65
50
36.8
1.2
10.62 3.98 × 10
-3
2.93 × 10
-3
12
5730
18,000
5
WB/PB 65