Distillation Process Analyzer DPA-4.5
Safety
2.4.4 Junction boxes (Ex e)
Figure 2.5: Signal junction box (1) and
power supply box (2)
The
signal junction box
contains terminals for
connecting the signal lines.
Note: The exposed
terminal connections are still live even when the
device is switched off.
Explosion protection is provided for the signal junction
box by the increased safety ignition protection (Ex e) in
closed condition only. Therefore:
•
Check that seals are intact.
•
Check whether the ground cable is screwed on. If
not, screw it on.
•
Keep the cover of the signal junction box closed with
all fastening bolts during normal operation.
The
power supply box
contains the terminals for
connecting the power supply, contactors and the APEX
control unit. It is required for the pressurization of the
control box. The control unit controls and monitors the
flow rate of the protective gas and the inner box
pressure during rinsing. During operation, only the inner
box pressure is monitored. During operation, the control
unit activates the voltages via the contactors.
Note:
The
exposed terminal connections are still live even
when the device is switched off.
The power supply box is open and closed using a
double-bit key.
Explosion protection is provided for the power supply
box by the increased safety ignition protection (Ex e) in
the closed condition only. Therefore:
•
Check that seals are intact.
•
Keep the power supply box closed during normal
operation.
2.4.5 Potential equalization
After installation, the frame and all box components are connected
to the local potential equalization rail.
•
Prior to commissioning, connect the device to the local
potential equalization rail.
•
Check the function of the potential equalization.
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