INDELAC CONTROLS 22018-DH, Инструкция по установке, эксплуатации и обслуживанию

Страница: 15 / 24

PART #22018-DH - High-Resolution Positioner
Page 15
ELECTRONIC BRAKE FEATURE:
The Electronic Brake feature of the DHC-400 provides highly reliable and accurate braking of the
motor, and it is a key element in achieving high resolution. A mechanical brake can still be
implemented without interfering with the DHC-400 operation. The Adaptive Control feature of the
DHC-400 automatically compensates for changes in a mechanical brake's performance due to
temperature or age.
Mechanical brakes can be useful for providing a holding brake in the event power to the actuator is
lost. However, mechanical brakes require time to release on motor start up, and this may cause an
increased surge current that counteracts the Electronic Surge Limiting feature. Also, a mechanical
brake may not release at lower voltages, in which case a stall or current trip fault may occur.
The Electronic Brake feature remains on as long as the DHC-400 is powered. This could make a
mechanical override mechanism difficult to turn. For this reason, the electronic brake is disabled
when the DHC-400 is placed in the Override Mode via J7 (see Special Applications).
CAUTION! When using the DHC-400 with a spring return actuator, the return spring can generate
high electrical energies while back driving the motor that can damage the DHC-400 motor outputs.
In this application, the motor must be disconnected (usually with a relay) from the DHC-400 during
a spring return operation.
DUTY CYCLE CONTROL FEATURE:
The Duty Cycle Control feature of the DHC-400 allows the actuator to be safely used when a
process becomes unstable, a control loop is not properly set, or when the motor is subjected to
excessive loading. The DHC-400 accurately monitors the relative heating of the motor and
automatically duty cycles the unit at a safe level.
The Duty Cycle Control feature allows continuous operation of the motor until it detects an excess
heat buildup in the motor. At that time, duty cycle operation is automatically enabled and continues
until the motor cools enough to resume continuous operation. The duty cycle period is approximately
2 seconds with an on time that automatically varies depending on the heating of the motor. While
this operation slows down the actuator's operation, it does not impact the resolution performance of
the DHC-400, and it allows control of the process to be maintained without damage to the motor.
SPECIFICATIONS:
POWER REQUIREMENTS

Operating Voltage: 10 to 30 VDC

Operating Current, typical: 70mA (not including option module)

Fuse Type: 10A TR5 Time Lag 374 (replaceable)