Samson Type 3766, Монтаж и эксплуатация

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4.4 Adjusting the position transmit-
ter
Important!
The starting point (zero) and upper range
value (span) must be set before calibrating
the position transmitter.
Depending on the position of the 4-pin plug
(symbol on plug: >> or <>), the feedback
signal can be set to either a range of 4 to
20 mA or 20 to 4 mA for 0 to 100 % travel.
Zero point (ZERO)
Use the switches 1 and 2 to preset the zero
point and the ZERO potentiometer for fine-
tuning. The adjusted value always refers to
4 mA.
Span (SPAN)
Use the switches 3 and 4 to preset the span,
i.e. the upper range value, and the SPAN
potentiometer for fine-tuning. The adjusted
value always refers to 20 mA.
Example:
Move the valve to open position while ob-
serving the position transmitter signal.
If the signal does not move in the desired di-
rection, switch over the multi-pin plug.
Adjust the zero point (4 mA) and span
(20 mA) for the valve positions according to
Table 10.
Fig. 15 ⋅ Position transmitter
Table 10 Position transmitter
Valve position Observed transmitter signal Direction of signal Set zero/span to
OPEN
CLOSED
Current increases ↑
OK
20 mA
4 mA
Valve OPEN
Valve CLOSED
Not OK
→
Reconnect plug
4 mA
20 mA
Valve OPEN
Valve CLOSED
Current decreases
↓
OK
4 mA
20 mA
Valve OPEN
Valve CLOSED
Not OK
→
Reconnect plug
20 mA
4 mA
Valve OPEN
Valve CLOSED
ZERO
SPAN
12
3
4
SPAN
ZERO
EB 8355-1 EN
37
Adjusting the position transmitter