RHEONIK RHE28, Инструкция по установке и запуску

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Appendix A: Safety Instructions – Ver. 1.00 30 / 43
***) The nominal signal Voltage between 70 and 71 is 3.3V. The interface is floating but clamped
to PE with a clamping voltage of 30V.
Applied voltages above the nominal voltage may damage the corresponding input or output but
will not affect the safety on the connection to the IS RHM or the IS pressure sensor.
Voltages above the Um values must be avoided.
Intrinsically safe I/O terminals for RHM:
RHM connections
Circuit name Terminals Uo [V] Io [mA] Po [mW] Lo [mH] Co [nF]
Drive circuit 1 - 2 8.1 136 275 1.9* 2000
Temp. sensor 3-4, 5-4 6.1 45.7** 69.7 1 2000
Pickup circuit 6-7, 9-8 2.4 9 5.4 100 2000
*) 7.5mH for sensors RHM certified for gas group IIB / group C and D.
**) PtP (Terminal 3) and PtT (Terminal 5) share a common ground PtG (terminal 4) The maximum
current on terminal 4 therefor is 91.4mA.
Analog 4-20mA input
Circuit name Terminals Uo [V] Io [mA] Po [mW] Li [mH] Co [nF]
Current Input 60 - 61 24.7 91.5 565 4.0 100
A.4 Thermal Safety Limits
The RHE28 with Ex-code A2, AB, C2 or CB have the temperature class T4
The RHE28 with Ex-code AS or Cs must be installed in the safe area, therefor no temperature
class is specified for these units.
The ambient temperature must under no circumstances exceed the limits specified in chapter
A.10.
A.5 Grounding and Shielding
The RHE28 must be grounded.
The minimum cross section of the ground wire is 2.5mm². Wires with 2.5mm² can be connected
to the PE terminal 22 or to the M4 screw type terminal. Wires with a bigger cross section must
be connected to the M4 screw type terminal.
Shield between RHM and RHE:
IEC60079-0 recommends to ground shielded cables just on one end, normally outside the
hazardous area. On the other side the shield may be grounded via a 1nF capacitor.
In small installations (cable length typically less than 10m) the shield can be grounded on both
sides, provided that there is no potential difference between PE at the RHM and PE at the RHE.
This can be assumed if there is a good metallic contact or if a dedicated PE cable of at least 4mm²
connects the two grounding points.