User`s manual

68
Magtrol WB/PB DynamometersChapter 4 – Connections / Configuration
4.3 CONNECTION TO NON-MAGTROL ELECTRONIC CONTROL UNITS
Caution: use extreme Caution when using eleCtroniC Control units not
provided by magtrol.
magtrol motor testing eleCtroniCs are fitted with safety deviCes
suCh as fuses, Current limiters, thermostats, etC. preventing the
dynamometers from operating outside of their limits.
Magtrol WB/PB Dynamometers are fitted with two types of connectors. The WB/PB 2.7 and
43 Series Dynamometers are fitted with LEMO type connectors and WB/PB 65, 115 and 15
Series Dynamometers use MS type connectors. Additionally, the available options vary from one
dynamometer to the other. Therefore, two or three different pin configurations are shown for each
connection.
4.3.1 P
oWer And thermoStAt connection
The PB Series Dynamometer torque depends exclusively on the excitation current, whereas the
torque of a WB Series Dynamometer is determined by both the excitation current and its speed.
Therefore, with WB Dynamometers, the excitation current must be reduced when its speed is being
increased to hold a constant torque.
To keep operating temperatures at acceptable levels, it is important to run dynamometers within
their power ratings. The breaking power of the dynamometer must therefore be regularly checked
by referring to the torque-speed-power rating curves shown in Section 2.10 of this manual or by
using the following equation:
Breaking Torque [N·m] × n [rpm]
Breaking Power [kW] =
9550
The thermostat is a normally closed contact which opens when a temperature limit of approximately
50 °C (120 °F) is reached. When this limit is reached, the excitation must be stopped.
Note: Unlike all other Magtrol WB/PB Dynamometers, the WB/PB 2.7
Series Dynamometers are not fitted with a thermostat. This function
is defeated by a short between terminal 1 and 2.