7.2.2
Replacing Power Supply Module
This section describes how to replace the power supply modules.
IMPORTANT
It is necessary to switch off the power supply before removing the power supply modules and
make sure that the power status indication LED is off.
If the power distribution unit of Yokogawa is used, the power supply of the power supply mod-
ule can be cut by disconnecting the power cable from the power distribution unit.
TIP
The specifications for the power supply module for ProSafe-RS I/O nodes are based on using a dual-redun-
dant configuration. You must observe this note if the processor module of the non-redundant safety control
unit or at least one of the processor modules of the dual-redundant safety control unit is as follows:
SCP401 of unit version "U:5" or earlier
SCP451 of unit version "U:4" or earlier
If an error occurs and only one of the paired modules powers up, or a power failure occurs on one module,
and you have no choice but to continue in the non-redundant state, the diagnostic information message (No.
0065) for the ESB bus interface module (SSB401) error might be generated for that node. After about one
second the system recovers. This phenomenon occurs very rarely and it does not indicate the abnormality of
SSB401 module and the related ESB bus and devices. It does not harm communication either.
Prevention:
The power supply modules should be kept in dual-redundant configuration.
Restoration:
If the abnormality indication disappears in a second, there is no need to do anything about it.
When one of the paired power supply modules fails, the failed module should be replaced with a good one as
soon as possible so as to return to the normal state (dual-redundant power supply configuration).
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Procedure for Removing Power Supply Modules
1. Shut off the power supply of the power supply module to be removed.
2. Disconnect the power cable from the power supply input terminals.
3. Remove the fixing screws of the power supply module. There is one at the upper part and
two at the bottom part.
4. Pull the power supply module forward and remove it from the base unit.
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Procedure for Installing Power Supply Modules
IMPORTANT
Use a phillips screwdriver or screwdriver to tighten the screws for fixing the power supply
module. As a guideline, the screw tightening torque should be approximately 0.5 N•m.
Install the power supply module following the steps of the "Procedure for Removing Power
Supply Modules" in the reverse order.
1. Install the power supply module on the base unit.
2. Fix screws in one place at the upper part and two places at the bottom part of the power
supply module.
<7.2 Replacing Common Modules >
7-8
IM 32Q06C10-31E
4th Edition : Jan.30,2015-00
