Instruction manual
OCM Pro CF
page 38
OCM Pro CF - Rev. 09 as of 07.06.2016
®
Fig. 7-14
Connecting external level measurement from NivuMaster to
type W0
7.2.3 Wall Mount Enclosure Overvoltage Protection
For effective protection of the OCM Pro transmitter it is necessary to protect
power supply as well as mA-output using overvoltage protection devices.
NIVUS recommends surge arrestors types EnerPro 220Tr, EnerPro 24Tr
(for 24 V DC) for the mains supply, as well type DataPro 2x1 24/24Tr for
mA-outputs.
The flow velocity sensor as well as the air-ultrasonic sensor type OCL are inter-
nally protected against overvoltage. If higher voltages are expected to occur they
can be protected by combining the types DataPro 2x1 12/12-11
μH-Tr (N) as well
as SonicPro 3x1 24 V/24 V
Important Note
If using the sensors in Ex areas consider the connected loads of the overvolt-
age protection devices as well as capacity and inductance of the NIVUS sen-
sor cables (POA, CS2, OCL, EBM) additionally!
The maximum permissible NIVUS cable lengths in Ex areas are:
-
single-side overvoltage protection: 135 m (443 ft.)
-
double-side overvoltage protection: 120 m (394 ft.)
Note
The use of overvoltage protection elements for sensors in Non-Ex areas will
reduce the maximum possible cable length.
The line resistance is 0.3 Ohm/wire. This resistance must be taken into ac-
count considering the allowed total resistance (see "Technical Instructions for
Correlation Sensors" for details)
Note
Observe the non-reversed connection (p-side to transmitter) as well as a cor-
rect, straight wiring supply.
Ground (earth) must lead to the unprotected side.
The overvoltage protection devices are ineffective if wired incorrectly!
Содержание OCM PRO CF
Страница 179: ...20 Certificates and Approvals...
Страница 180: ......
Страница 181: ......
Страница 182: ......
Страница 183: ......
Страница 184: ......
Страница 185: ......
Страница 186: ......
Страница 187: ......
Страница 188: ......
Страница 189: ......
Страница 190: ......
Страница 191: ......
Страница 192: ......