Sine Systems RFC-1/B Instruction Book

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the supplied transformer is of the type that has a connector on the end of the cord, simply cut
the connector off and discard it.
In installations where 120 volts AC is not available, the RFC-1 may be powered by any
transformer delivering 12.0 to 14.2 volts AC (50 - 60 Hz) or any DC power supply delivering
15.4 to 17.5 volts DC. The RFC-1 draws a maximum of 0.35 amperes. A 12.6 volt “ filament ”
transformer is an ideal substitute power source. The power source should be “ floating."
Neither side of the power source should be connected to ground (earth) nor should the power
source be connected to any other equipment. Failure to do this will result in inaccurate
telemetry indications.
/ 1\ WARNING!
L — - — X Before power is applied initially, check the "12 VAC"
terminals with an ohmmeter for a short circuit. Make this test with the flat
cable plugged into both the RFC-1 and the RP-8 panel(s). If a short is detected,
it is likely that one of the flat cable connectors has been installed backward. Do
not connect the wall-plug transformer until the problem is found and
corrected.
Telemetry Connections
Telemetry connections are made on the RP-8 panels through the eight terminal blocks located
across the top of the panel marked "Telemetry." The channels on the panel are identified as
"00" through "07" but this would be the correct numbering only if it was assigned to the first
"block. ”
The RFC-1 can telemeter either a positive or a negative voltage source. One volt DC is the
minimum voltage required for a full scale reading but a lower voltage will be sufficient if less
than a full-scale reading is satisfactory.
The telemetry terminal blocks are marked and "+". Connect the positive side of the
telemetry source to the "+" terminal and the negative side to the terminal. Either side may
be ground referenced, if desired, or the telemetry source may be offset from ground up to 30
volts.
High telemetry voltages (4 volts or greater) will cause the active range of the calibration
potentiometers to be limited to the bottom few turns of the 22 turn total range and make
calibration "touchy." For this reason it is suggested that high telemetry voltages be
attenuated with an external attenuator. The best way to accomplish this is to add a 2.2K
resistor shunted across the RP-8 telemetry terminals and a series resistor connected to the
telemetry source. The series resistor should be about 2200 ohms per volt in excess of two
volts. For example, to attenuate a telemetry voltage of 10 volts, use a 2.2K shunt resistor
and a 18K series resistor. The values are not critical.
Shielded wire for telemetry circuits is not normally necessary as a considerable amount of
RFI filtering is included in the RFC-1. However, lines from AM sampling loops in some
installations may contain a very large amount of RF which can cause telemetry linearity or
other problems. RF chokes of about 2.5 millihenrys inductance inserted in each telemetry
lead should eliminate this problem.
3.00.2
Installation
page 5.4

Sine Systems RFC-1/B Specifications

General

Brand	Sine Systems
Model	RFC-1/B
Category	Remote Control
Language	English