Page 76 - Offshore Electrical Engineering Manual
P. 76
Starting Requirements 63
Engine
N Busbars
Earth bar
FIGURE 2.4.3
Low-voltage solidly earthed arrangement.
current magnitudes and circuit breaker tripping times. Because of the marine envi-
ronment, earthing resistors tend to deteriorate quite quickly and require very regular
maintenance (in the author’s experience, at least once a year).
STARTING REQUIREMENTS
At some stage in the design of the platform power system, it is worthwhile carry-
ing out a Failure Modes, Effects and Criticality Analysis (FMECA) of the system
to ensure that as many operational problems can be foreseen, and catered for, in the
design as possible. The FMECA methods are discussed in PART 8 Chapter 1.
Consideration of operational problems is especially important when provid-
ing for the bringing of generators into service when all or most platform services
are unavailable, i.e., black-start facilities. Although written black-start procedures
should be available to the operators, these should reflect the permanent facilities
installed. Black starting cannot be safely or adequately catered for by describing
some temporary rig in the ‘Installation Standing Instructions’. For example, the
installation manager would not thank the system designers if in certain conditions
