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HVG-2020B Instruction Manual
EAR99 Technology Subject to Restrictions Contained on the Cover Page
Page 10 of 40
2.2.2. Plumbing
Mount the gauge as close as possible to the to the pressure area of interest. Long or restricted tubing will
create a pressure difference between that area and the gauge. Mounting too close to gas sources can also
affect pressure measurement.
The HVG-2020B can come with any of several vacuum connections, including: 1/8” NPT, ¼ VCR, ½” VCR, KF-
16, KF-25, 1.33” CF, 2.75” CF and ½” smooth stub tube. The tube is configured with the vacuum fitting
requested.
NOTICE:
When installing the 1/8” NPT version, be certain to use the ½” wrench flats. Do not tighten
using the aluminum housing as a grip or damage may result.
WARNING:
Do not exceed the pressure rating of the instrument. If operating near the maximum
operating pressure, ensure there is a pressure relief valve in the system.
Electrical Connections
WARNING:
Care must be taken to avoid any high voltages that may be present when dealing
with power supplies.
2.3.1. Connector
The HVG-2020B 9 pin “D” connector pin assignments are listed here.
NOTICE:
The cable length must be less than 30 meters long (unless
housed in a metal conduit) to meet CE Mark requirements.
2.3.2. Power Input
The HVG-2020B has its own internal switching power supply and requires between 12 and 36 VDC input voltage.
The +VDC supply is pin 3 and the –VDC return is pin 4. Case ground is pin 6.
NOTICE:
Either the base or pin 6 must be connected to ground for proper noise immunity and to meet
CE Mark standards.
There is also a 2mm barrel connector available as a 24 VDC power jack. The center pin polarity is positive and
is internally connected to pin 3 of the “D” connector. The sleeve is internally connected to pin 4 of the “D”
connector.
The gauge requires a maximum of 2.1 watts for proper operation. Surge suppressors are recommended to
prevent power spikes reaching the instrument. Hastings power supplies satisfy these power requirements.
Pin #
1
High Setpoint
2
Low Setpoint
3
+ Power (12-36 VDC)
4
Power/Digital Common
5
Analog Output
6
Case Ground
7
Tx out (TTL)
8
Analog Common
9
Rx in (TTL)