Form # 1925 Rev. 4/06 TESCOM
GENERAL OPERATION
Continued
2
EXTERNAL FEEDBACK MODE
In External Feedback mode, the ER1200 can
be used to control flow, position, temperature,
or any other variable that can be affected by a
change in pressure. For the purpose of this
operation manual, we will discuss the control
of pressure. In this mode, the ER1200
compares an external feedback signal from a
customer supplied transducer to the setpoint.
Typically, this mode is used when the ER1200
is combined with either a pressure reducing or
back pressure regulator
(shown with a ratio
actuated, pressure reducing regulator, Figure 2)
.
If the feedback signal is below setpoint, the
ER1200 opens its inlet valve and increases
output pressure. This increases pressure on
the dome of the regulator, opening the main
valve and increasing downstream pressure. If
the feedback is above setpoint, the ER1200
opens its exhaust valve, which decreases
dome pressure, allowing the regulator to
decrease output pressure.
Pressure Connections:
ER1200 inlet pressure is the same as in
internal mode. Refer to regulator installation
and operation instructions and the product
label for maximum inlet pressure information.
Figure 2
