Yokogawa RAKD User Manual
Page 52
<8. EXPLOSION-PROTECTED TYPE INSTRUMENTS>
8-6
IM 01R01B30-00E-E 5th edition January 01, 2013 -00
All Rights Reserved. Copyright © 2003, Rota Yokogawa
Intrinsic safe power supply for the electronic transmitter :
The power supply for the electronic transmitter is an associated apparatus that may not be installed in the hazardous
area, and it may not exceed the safety relevant maximum values for voltage, current and power of the electronic
transmitters as specified above. The internal capacity or inductivity of RAKD inclusive cable may not exceed the
external capacity or inductivity of the power supply.
For example the type RN221N-B1 (Option /U__) with certificate PTB 00 ATEX 2018 can be used.
Intrinsic safe power supply for the limit switches :
The power supply (transmitter relay) for the limit switches is an associated apparatus that may not be installed in
the hazardous area, and it may not exceed the safety relevant maximum values for voltage, current and power of
the connected limit switch as specified above.
For example the type KFA6-SR2-Ex... (option (W2_) according certificate IECEx PTB 11.0031 (230V AC supply)
or the type KFD2-SR2-Ex... (option (W4_) according certificate IECEx PTB 11.0034 (24V DC supply) can be used.
Temperature specification:
Table 8-2
Configura-
tion
Max.
ambient
temperature
Max.
process tem-
perature
Temperature
class
Transmitter
4-20mA /
Pulse
65°C
65°C
T6
50°C
80°C
45°C
100°C
T5
38°C
135°C
T4
Limit
switch(es)
type 2
65°C
65°C
T6
80°C
80°C
T5
59°C
100°C
100°C
100°C
T4
73°C
135°C
Limit
switch(es)
type 3
24°C
65°C
T6
37°C
80°C
T5
34°C
100°C
57°C
80°C
T4
54°C
100°C
48°C
135°C
For the configuration where a transmitter is combined with limit switches, the temperature class is determined by
the most restrictive combinations of maximum ambient temperature and maximum process temperature.
Description of limit switch type 2 and 3 see ATEX certificates from Pepperl & Fuchs:
- IECEx PTB 11.0091X (SC2-NO) for /K1 to /K3
- IECEx PTB 11.0092X (SJ2-S.N) for /K6 to /K10