Alstom SHPM 101, Service Manual

Page: 322 / 336

SERVICE MANUAL R5888B
QUADRAMHO Chapter 7
Page 2 of 2
Section 4. CASE IDENTIFICATION CODING
The four letter code identifying an auxiliary subrack assembly are specified as
follows. The first letter is always Z, the second letter is D if the case height is one
subrack and K if it is two. The third letter denotes the number of modules, B for
one, C for two etc, vowels not being used. The fourth letter indicates application:
D for distance relay application
T for tripping application
X for general purpose.
Section 5. MODULE POSITIONS
The position of a module in a subrack is designated by a number. Module 1 in an
equipment is the module at the top left hand side of the case, viewing from the
front. If the protection is split into more than one complete unit, then each unit will
have an equipment number which will appear with the module number. Thus
module 1 in equipment 1, is module 1.1 and module 2 is module 2.1, etc.
Each module will connect with at least one edge connector and in a subrack
diagram the position of an edge connector has a designation, eg Z25M. This
signifies that the edge connector is on the upper subrack (Z), the lower ones being
Y, X etc, in turn, in a multi-tier equipment. The figure 25 indicates that the edge
connector is 25 modular pitches from the left hand side of the case, again looking
at it from the front. There are a total of 48 modular pitches in the full width case.
The letter M identifies the whole designation as an edge connector position in a
modular case.
A case or subrack circuit diagram will identify modules by:
• The 3 alpha reference
• The module number in the case
• The edge connector positions in terms of modular pitches
It will show the interconnection between module edge connectors and the
connections between edge connectors and case terminals.