Aalborg SMV Series - Manual (Page 6)

2. INSTALLATION
2.1 Primary Gas Connections
Prior to connecting gas lines inspect all parts of the piping system including
ferrules and fittings for dust or other contaminants. Be sure to observe the
direction of gas flow as indicated by the arrow on the front of the meter when
connecting the gas system to be monitored.
Insert tubing into the compression fittings until the ends of the properly sized
tubing home flush against the shoulders of the fittings. Compression fittings
are to be tightened according to the manufacturer's instructions to one and
one quarter turns. Avoid over tightening which will seriously damage fittings.
SMV Motorized Valves are supplied with standard 3/8 inch (SMV-20), 1/2
inch (SMV-30), or 3/4 inch (SMV-40) inlet and outlet compression fittings.
Using a Helium Leak Detector or other equivalent method perform a thorough
leak test of the entire system. (All SMV's are checked prior to shipment for
leakage within stated limits. See specifications in this manual.)
2.2 Electrical Connections
The motorized valve requires a +12VDC power supply with a minimum cur-
rent rating of 800 mA. Operating power and valve control signals are supplied
via the 9-pin "D" connector located at the side of the valve. For normal oper-
ating the motorized valve requires at least two control signals:
l Direction (12V CMOS logic level, pin 8 on the 9-pin "D" connector)
l Speed (0-2.5 VDC analog signal, pin 4 on the 9-pin "D" connector)
When direction is LOW (GND) valve goes down (closes), when direction is
HIGH valve goes up (opens). The "speed" voltage on pin 4 determines how
quickly the valve will operate. The signal amplitude for "speed" control signal
must remain within the limits of 0 to +2.5 VDC.
It may be necessary to override "direction" and "speed" signals with a preset
(2.75 VDC) speed control signal. This can be accomplished with valve CLOSE
and PURGE control signals (open collector NPN compatible). In order to
CLOSE valve pin 3 on the 9-pin "D" connector has to be connected to GND
(pin 2). A GREEN light on the top of the valve will indicate a CLOSE valve
condition. In order to PURGE valve pin 7 on the 9-pin "D" connector has to be
connected to GND (pin 2). A RED light on the top of the valve will indicate a
fully OPEN valve condition.
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