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IRDOT-P TERMINALS:
"R" These two terminals are used to connect power to the point motor.
When the IRDOT-P first detects a train the "R" terminals are connected
together. After approx. 1 second the IRDOT-P removes the connection
between the terminals. Whether the train stops over the IRDOT-P or continues
to move the point motor is only powered for 1 second. Also there is a dead
time of approx. 4 seconds before the "R" terminals will operate again.
The 1 second timing and the dead time prevent the point motor from damage
by being continually powered. The IRDOT-P makes this connection between
the "R" terminals with its internal relay contacts. The relay contacts
are of 10 amp capacity allowing at least four point motors to be
switched.
Using a relay keeps the IRDOT-P power supply and the point motors power
electrically separate. The terminals act as an automatically operated passing
contact switch. The diagram shows two point motors controlled by two IRDOT-Ps.
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SOLENOID POINT MOTORS How they work and are wired
The common (middle) connections of the point motor are all wired straight
back to the point motors power. When the top IRDOT-P detects its "R" terminals
will be
temporarily connected giving a burst of power to the left hand connection
of both point motors, switching the points left. When the bottom IRDOT-P
detects it will switch both point motors right.
"LED": this lights an LED (supplied fitted) while the IRDOT-P detects a train. Long leg of the LED to "LED" short leg to "-". This LED is useful during installation. It can be wired to the control panel if required.
"V0" and "+" these terminals are for connection to a power supply to power the IRDOT-P. It may be powered from 12 to 16 volts AC or DC. This supply is separate from the one used for the point motors. "P" on first detecting a train, this terminal switches to 0 Volts for approx. 1 second. Its purpose is to operate other units such as the Dual Timer, latching relays, SA1 shuttle and SA6 when the IRDOT-P detects a train.
": Terminal. "I" (inhibit) stops the "R" and "P" terminals operating when it is connected to 0 volts. The train detected LED still lights when "I" is used. A switch, SA6, IRDOT, Dual Time Delay board, relay, or Train Direction Detector can be used to operate 'I'. This terminal is used to automatically stop the IRDOT-P from operating the point when a train is in a certain place or travelling in a certain direction. "I" is also used for changing from automatic to manual point operation.
TRAILING POINTS: This is the simplest installation. The IRDOT-P is arranged so that trailing points are always correctly set. If required they can be set manually for the facing direction.
COMPLICATED ROUTES:
An example of how two IRDOT-Ps can make a train alternate between two different routes is shown. The IRDOT-P at B switches point 1 for the outer oval and point 2 for the inner. The IRDOT-P at A switches point 1 for the inner oval and point 2 for the outer. The effect of this is for the train to make alternate laps around the outer and inner lines. This idea can be extended to more complex arrangements.
CHANGE OVER TO MANUAL CONTROL: One switch is used to connect all the "I" terminals to 0 volts (terminal "V0"). When the switch operates, the IRDOT-Ps no longer control the points. A manual point switch is wired to the two "R" terminals.
SLOW MOTION POINT MOTORS:
We can supply the IRDOT-P modified to close its relay for approximately 20 seconds. This allows sufficient time to operate slow motion point motors.
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