Xylem 600026, Руководство по эксплуатации

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Turb PLUS 2000 Installation
20 100193 Rev 0 ba77254e01 11/2020
are on the upper row. The RS-485 and 4-20mA are on the lower row.
These connections are rated for a wire size from 12-28 AWG, either solid or stranded.
Alarm and I/O Connections
•
The Alarm 1 and Alarm 2 relays are mechanical relays rated at 120-240 VAC 2A.
• Note that the relays are labeled NO (Normally Open), NC (Normally Closed) and C (Common).
•
The normal condition is with power applied to the Turb PLUS 2000 and in a non-alarm condition.
Operation of these alarms is covered in section 4.2.4
Configuring the Alarms
.
•
Connections are labeled beneath the large terminal block. These connections are on the upper row.
RS-485/Modbus Connection
•
The RS-485 half-duplex (2-wire) digital interface operates with differential levels that are not
susceptible to electrical interferences. Cable lengths up to 900 meters (3000 ft.) can be
implemented.
•
The last device on each bus may require terminating with a 120-ohm resistor to eliminate signal
reflection on the line.
•
Do not run RS-485 cables in the same conduit as power.
•
Ensure that power is disconnected prior to making connections to present damage to the
instrument.
•
Connections are labeled beneath the large terminal block. These connections are on the left side
on the lower row.
4-20 mA Connection
DANGER
Make sure the Turb PLUS 2000 is disconnected and not powered
BEFORE connecting the 4-20 mA.
•
The 4-20 mA output is driven by a 24 VDC power source and can drive recorder loads up to 1000
ohms.
• This 4-20 mA output is isolated from line power and earth ground.
•
Do not run 4-20 mA cables in the same conduit as power.
• Connections are labeled beneath the large terminal block. These connections are on the right side
on the lower row.
•
Operation of this output is covered in section 4.2.1
Setting the 4-20 mA
.