Push/Pull Switch - Non-Nfpa Installations; Remote Controls (Hand Held) - Will Burt Night Scan Chief Installation, Operation & Maintenance Manual

control by pulling the switch operator. This is a momentary function, and the switch will return itself to a
neutral position on its own. Secondly, it functions as an emergency stop when the switch operator is pushed
all the way in. This is also a momentary function, and the switch will return itself to a neutral position on its
own. When using Will-Burt's accessory kit push/pull switch, accidental initiating is extremely unlikely since it
would require pulling the switch button. Even with this, the Remote Control(s) would have to be subsequently
pushed to get any action. In the unlikely event that the initiate switch were engaged, the Night Scan will power
itself down if no Remote Control action occurs within thirty seconds. The "Push" portion of the Push/Pull
switch functions as an Emergency Stop. If it is pushed, the mast will immediately be disconnected from power
and stop. It should be noted that prematurely disconnecting power in this way will immediately cause
the mast to vent. Other interlock contacts could be inserted into this circuit to provide additional safety. The
control also monitors the initiate input, and if it sees that this input is present for a prolonged period of time;
the control will stop the mast and appropriate error code will be displayed (Err, 1.09). This is a preventative
measure to ensure the initiate input is not hot-wired. Once the mast has been initiated, the Remote Control
must then be used to begin raising the mast within thirty seconds or the control will shut itself down. If the
mast has been initiated and raised any amount, the control will remain powered until the mast is fully stowed,
the emergency stop function is used, or the power is somehow otherwise interrupted.
3.4 PUSH/PULL SWITCH – NON-NFPA INSTALLATIONS
All operation of a completely stowed mast must be preceded by proper initialization. The initiate switch must
be closed to power-up the Night Scan. When the Will-Burt Accessory Kit is used, the Push/Pull switch is
located on the junction box. It is used to perform two functions. First, it can be used to "initiate" the control by
pulling the switch operator. Secondly, it functions as an emergency stop when the switch operator is pushed
all the way in. When using Will-Burt's accessory kit push/pull switch, accidental initiating is extremely unlikely
since it would require pulling the switch button. The "Push" portion of the Push/Pull switch functions as an
Emergency Stop. If it is pushed, the mast will immediately be disconnected from power and stop. It should
be noted that prematurely disconnecting power in this way will immediately cause the mast to vent.
Other interlock contacts could be inserted into this circuit to provide additional safety.

3.5 REMOTE CONTROLS (HAND HELD)

Wired Hand Held Remote Control
•
The Remote Control accepts switch activations from the operator and translates them into
serial commands for transmission to the base control board via the RS-485 link. If the operator
engages a switch, the Remote Control will appropriately send commands repeatedly as long as
the operator continues to engage that switch. The Base control will pass along appropriate
serial commands to the RCP in response to the Remote Control(s). Additionally, various states
of the system will be passed to the Remote Control so that button status LEDs can give proper
indication of the state of the Night Scan. An example of this is that the LED next to the "Mast
Down" button will not be lit unless it is appropriate to lower the mast. Upon first beginning to
raise the mast, it will be noted that the "Mast Down" button does not become active until a
certain amount of movement has been accomplished. This is to ensure that there is enough
downward travel available for proper stowing of the mast. If the button status LED for a
particular button is not lit, that button will not function. Another reason for a button status LED
not being lit could be an actuator reaching the extent of its travel (or limit switch).
•
Two special functions are implemented in software whereby the operator can initiate an
unattended lowering and stowing of the mast, or an unattended partial raising of the mast. The
Autostow is accomplished by two rapid sequential activations of the "Mast Down" button within
a half second period of time. This automatic unattended sequence can be aborted at any time
by a single activation of the "Mast Up" button or any other button on the Remote Control(s). The
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Night Scan Chief
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