10
3 Safety instructions
The use of radio remote controllers lightens the load of daily work, while increasing
the daily yield.
However, in contrast to when the operator is standing next to the skidder, operating
the winches manually, the operator may be some distance away and may not be able
to appreciate the tension or strain on a winch cable, or the pull on the skidder. This
increases the chance of the system being overloaded, in which case the cable can
snap or the skidder can turn over.
It is for this reason that the operator is urged to keep a good distance from the
skidder and from loads pulled by the winches. He should keep at least half a cable
length from the whole system!
If a load becomes jammed, and the operator goes forward to work on it, the receiver
should be switched into the standby mode by pushing the Stop button on the hand-
held transmitter (see section 4.2).
The operation of the HM22xx radio remote control systems was designed to eliminate
the adverse of dangerous effect of interference or malfunction.
HM-Funktechnik, however, strictly recommends that if a user has any problems with a
unit it should be taken out of operation. It should then be checked by a skilled and
experienced electronic engineer, or sent to the service agent.
4 The receiver unit
4.1 Safety functions
4.1.1 Self test
The receiver has two main safety functions:The first is a continuous monitoring of the circuit
operation. If at any time the system detects a malfunction, the receiver unit will be switched
off automatically. The second safety feature is that the operator can isolate the control
output voltage from the control relays at any time. This function disables all the control
outputs, so that the remote control of equipment is disabled.
4.1.2 Control isolation
The output relay bus-bar voltage is available externally (units with a 13 pin plug only). This
allows the connection of a status indicator, for example a lamp on the back of the vehicle, to
show the operator the current status of the receiver unit. This would be a safety tool, as it
indicates to the operator whether the system is in the standby mode or in the active mode.
The receiver is programmed to test these two safety functions periodically.
4.1.3 Manual alarm function
The HM22xx systems have a manual or passive alarm operation. To activate the manual
alarm the operator must press the
Stop
button while holding down the
Hupe
button on the
transmitter. This will switch the external alarm relay and can be used to trigger an
emergency call system, such as the HM WECC2.
Summary of Contents for HM 2225
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Page 18: ...18 10 Block diagram of the receiver ...
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