Optional Switch Load Limits; General Configuration Notes - Baker Hughes Masoneilan SVI II ESD Quick Start Manual

B. Optional Switch Load Limits

General Configuration Notes

The SVI II ESD 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 23).
+
SVI II ESD
Switch
Output
-
Figure 23 Switch Installation Drawing without Load: Configuration
V
SWITCH
I
SWITCH
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Full voltage
drop is
occurring
across the
switch (no
current limit in
place)
Switch OFF
30 VDC max.
 0.200 mA (Switch leakage current) 1 A max.
CAUTION
NOT ALLOWED
 1 V (Switch saturation voltage)
Incorrect polarity connection results in an
effectively closed connection.
Masoneilan SVI II ESD Quick Start Guide =| 93
.
+
External
Voltage
Source
-
Not Allowed
Switch ON