Uninterruptible Power Supplies and Standby Power Systems
Written by two experienced engineers, this book covers rotary UPS systems and battery selection, and offers complete, up-to-date guidance on design, installation, operation, and maintenance.
TABLE OF CONTENTS Uninterruptible Power Supplies and Standby Power Systems
The Power Rating Classification of Diesel Engine Driven Generating Sets
Rating classes applicable to diesel engine driven generator sets are described in ISO 8528 and are discussed in the following paragraphs. None of the ratings include any overload capacity.
Continuous Power (COP)
Continuous power (Fig. 1.1) is the power which the set can deliver continuously for an unlimited number of hours per year between the stated maintenance intervals.
Figure 1.1: Illustration of continuous power.
Prime Power (PRP)
This rating is applicable to sets supplying a variable power sequence. The sequence may be run for an unlimited number of hours per year between the stated maintenance intervals. Prime power is the maximum power generated during the sequence and the average power over any 24-hour period is not to exceed a stated percentage of the prime power. In calculating the average power, powers of less than 30 percent shall be taken as 30 percent and any time at standstill shall not be counted. The example of generating set sizing which appears in Chap. 3 uses prime power rating.
As the 24-hour average power of a PRP-rated set is increased, it becomes closer to a COP rating; if the average power is equal to the prime power the set would in effect be rated for continuous power.
This rating is suitable for standby supply generating purposes. The prime power is available for peak loads which occur after start-up such as motor starting and UPS battery charging. and after these loads have reduced, the...
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