Baker Hughes Masoneilan SVI II AP, Быстрый старт

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Masoneilan SVI II AP Digital Positioner Quick Start Guide = | 95
© 2018 Baker Hughes, a GE company, LLC. All rights reserved.
General Configuration Notes
The SVI II AP supports two identical contact outputs, SW #1 and SW #2 (Digital Output switches),
that can be logically linked to status bits.
The switches are polarity sensitive and must be connected only to a DC circuit. The switch (+) ter-
minal must be electrically positive with respect to the (–) terminal. If the (+) terminal is electrically
negative with respect to the (–) terminal, then the switch will conduct, regardless of switch state.
If the switch is connected directly across the power source, the current will be limited only
by the capacity of the power source and the switch can be damaged.
This section discusses the necessary precautions when configuring a system.
Without a load, when the switch is on (closed) the external voltage would be dropped across the
switch.
This damages the switch (Figure 34).
Figure 34 Switch Installation Drawing without Load: Configuration Not Allowed
Switch OFF Switch ON
V
SWITCH
30 VDC max.

1 V (Switch saturation voltage)
I
SWITCH

0.200 mA (Switch leakage current) 1 A max.
SVI II AP
Switch
Output
External
Voltage
Source
NOT ALLOWED
Full voltage
drop is
occurring
across the
switch (no
current limit in
place)
+
-
-
+
B. Optional Switch Load
Limits