Endura APA592
pH / Redox (ORP) transmitter
4 Electrical Installation
OI/APA592–EN Rev. E
33
4.8 Power Supply Requirements
4.8.1 Standard Application
When connecting APA592–PH transmitters and power supplies in non-hazardous areas, observe the
following specification:
U
Smin
U
Mmin
+ 0.022A x R
Ltg
Where:
For HART functionality, use power supplies or SPS input cards with HART mark. If this is not possible, the
interconnection must have a resistance of 250
(< 1100
).
The signal line can be connected with or without an earth (ground) connection. When connecting the earth
(ground) (minus side), ensure that only one side of the contact is connected to an equipotential bonding
system.
Warning.
The connection terminals accept cables with a maximum peripheral wire cross-section of 2.5 mm
2
12 SWG (10 AWG).
Switch off the power supply before connecting the transmitter.
Notes.
To ensure the sensor cable length is sufficient, allow an additional 100 mm (4 in.) of cable to pass
through cable glands and into the housing.
Use stranded conductor material for the power supply cable.
Ensure the connecting cable is flexible.
Do not use a rigid conductor material as this can result in wire breaks. Ensure the connecting
cable is flexible.
U
Mmin
–
Minimum operating voltage of transmitter
(refer to technical data for transmitter)
U
Smin
–
Minimum supply voltage of power supply/SPS input
R
Ltg
–
Line resistance between transmitter and power supply
Fig. 4.7 Standard Application
+
+
Transmitter
Power Supply /
SPS Input with Supply
U
Mmin
U
Smin
R
Ltg
Control Room
