STATUS SCIENTIFIC CONTROLS MCU3 - Page 26

STATUS SCIENTIFIC CONTROLS
MCU System Installation and Hardware Configuration Manual
TD06/001
Issue:
6
Change Note:
1696
Page 3-8
The I.S Earth connection on the power distribution PCB must be connected to the I.S. earth point
for the installation. The connection must be made via a conductor of minimum 4mm
2
cross
sectional area. Refer to EN60079-14 (previously BS5345:Part 4, section 16) for further details of
earthing requirements.
The barrier has two outputs having the following electrical parameters:-
Channel 1 Output, Terminals 1 & 2: 28V DC
0.112 Amps
0.8 Watts
Internal Resistance = 270Ω ±5%
Channel 2 Output, Terminals 3&4: 7.5V DC
0.66 Amps
1.24 Watts
Internal Resistance = 12Ω ±5%
In order to maintain intrinsic safety, the capacitance and Inductance or Inductance to Resistance
(L/R) ratio of the loads connected to the terminals of the FGDIO Barrier must not exceed
specified values:
The capacitance and Inductance or Inductance to Resistance (L/R) ratio of the load connected to
terminals 1 and 2 must not exceed the following values:
GROUP
CAPACITANCE
in F
INDUCTANCE
in mH
OR
L/R RATIO
in H/ohm
IIC
0.083
3
44
IIB
0.65
12
177
IIA
2.15
25
355
The capacitance and Inductance or Inductance to Resistance (L/R) ratio of the load connected to
terminals 4 and 3 must not exceed the following values:
GROUP
CAPACITANCE
in F
INDUCTANCE
in mH
OR
L/R RATIO
in H/ohm
IIC
11.1
0.07
28
IIB
174
0.28
114
IIA
1000
0.56
228
Warning:
When considering the suitability of an installation in terms of the load capacitance and
inductance, account must be taken of the interconnecting cable itself. The figures in the tables
must not be exceeded by the combination of the load parameters and the cable parameters. This
may restrict the permissible cable length in some applications. If in doubt, consult Status
Scientific Controls for assistance.