P74x/EN TS/N
1, P742, P743 
(TS) 12-
 
1.  INTRODUCTION 
Before carrying out any work on the equipment, the user should be familiar with the 
contents of the safety section/safety guide Pxxx-SG-4LM-2 or later issue, the technical 
data section and the ratings on the equipment rating label. 
The purpose of this section of the service manual is to allow an error condition on the relay 
to be identified so that appropriate corrective action can be taken.  
Should the relay have developed a fault, it should be possible in most cases to identify which 
relay module requires attention.  The Maintenance section (P74x/EN MT), advises on the 
recommended method of repair where faulty modules need replacing.  It is not possible to 
perform an on-site repair to a faulted module.  
In cases where a faulty relay/module is being returned to the manufacturer or one of their 
approved service centres, completed copy of the Repair/Modification Return Authorization 
Form located at the end of this section should be included.