how to water treatment plant electrical maintenance
- last year
Electrical maintenance and safety in any plant depend on three main fac tors: (a) the design and installation of equipment, (b) the training of op erating personnel, and (e) the quality of the maintenance program.
Design
To insure safe operation and mini- mum maintenance costs, the following design considerations are of prime immensely in power requirements, de- portance:
1. The choice of the type and voltage of the system must be based on a sound evaluation of initial loads with ade quate provision for future expansion; 2. Careful selection of equipment
Generally speaking, small and me dium-sized plants which are not spread over too wide an area can readily be supplied from a single substation at 440 v. The largest motor which would normally be operated on a 440-v system is 150 hp. Larger plants spread over a wider area and employing larger motors should go to a higher distri- bution voltage-2,400 or 4,160 v, with 4. Adequate grounding of system motors above 150 hp operating directly on distribution voltage, and smaller motors operating at 440 v through step- down unit substations or power een-
and wiring components; 3. Proper grouping of equipment on feeder circuits and load centers with respect to normal sequence of opera-
tion;
and equipment; 5. Location and protection of con-
trol equipment; 6. Provision for emergency power ters. for preferred circuits; and
As to reliability, this brings up the 7. Suitable alarm and signal eir question of whether to use a simple radial distribution system, or a split system with more than one primary feeder and tie circuit breakers. There To select the proper type and voltage are several variations which might be used, depending on the degree of sys-
cuits.
Distribution System
for the distribution system, the de- signer must have complete information as to the total connected loads, maxi- mum horsepower of individual motors, sequence of operation, and the degree of reliability required for the plant.
The degree of system-reliability de- *Presented at the 31st Annual Conference, California Sewage and Industrial Wastes Assn.; Long Beach, Calif.; Apr. 29-May 2, 1950.
pends directly on the economics of the situation: how much can the client af- ford to pay for reliability? There are no set rules of thumb to cover this point. Each plant must be considered on its own merits. Neither are there any reliable rules of thumb for esti mating in advance the approximate horsepower required for a particular plant. Similar plants will vary im pending upon topographic location and the
Design
To insure safe operation and mini- mum maintenance costs, the following design considerations are of prime immensely in power requirements, de- portance:
1. The choice of the type and voltage of the system must be based on a sound evaluation of initial loads with ade quate provision for future expansion; 2. Careful selection of equipment
Generally speaking, small and me dium-sized plants which are not spread over too wide an area can readily be supplied from a single substation at 440 v. The largest motor which would normally be operated on a 440-v system is 150 hp. Larger plants spread over a wider area and employing larger motors should go to a higher distri- bution voltage-2,400 or 4,160 v, with 4. Adequate grounding of system motors above 150 hp operating directly on distribution voltage, and smaller motors operating at 440 v through step- down unit substations or power een-
and wiring components; 3. Proper grouping of equipment on feeder circuits and load centers with respect to normal sequence of opera-
tion;
and equipment; 5. Location and protection of con-
trol equipment; 6. Provision for emergency power ters. for preferred circuits; and
As to reliability, this brings up the 7. Suitable alarm and signal eir question of whether to use a simple radial distribution system, or a split system with more than one primary feeder and tie circuit breakers. There To select the proper type and voltage are several variations which might be used, depending on the degree of sys-
cuits.
Distribution System
for the distribution system, the de- signer must have complete information as to the total connected loads, maxi- mum horsepower of individual motors, sequence of operation, and the degree of reliability required for the plant.
The degree of system-reliability de- *Presented at the 31st Annual Conference, California Sewage and Industrial Wastes Assn.; Long Beach, Calif.; Apr. 29-May 2, 1950.
pends directly on the economics of the situation: how much can the client af- ford to pay for reliability? There are no set rules of thumb to cover this point. Each plant must be considered on its own merits. Neither are there any reliable rules of thumb for esti mating in advance the approximate horsepower required for a particular plant. Similar plants will vary im pending upon topographic location and the