Page 207 - Industrial Power Engineering and Applications Handbook

Special-purpose motors 7/187

-
F4
Y
1 1
NL

‘6

1st motor (Off-delay) On Off O/C
+ trip
inst.
I

1 1
);id,

2nd motor I I h2 13
(On-delay) (Off-delay) On Off O/C
+ trip
inst.
inst. - instantaneous
Figure 7.20 A typical scheme illustrating re-acceleration of two motors (or two groups of motors) with a time gap

Table 7.7 Preferred speeds for thermal power station auxiliaries Table 7.8 Recommended enclosures and type of cooling for
power station auxiliaries
Auxiliury Synchronous
speed (rp.rn.) Enclosure Type of cooling
us in
Induced-draught fan (ID fan) 750, 1000 IEC 60034-6
Forced-draught fan (FD fan) 1000, 1500
Primary air fan (PA fan) 1500 1 TEFC IC 0141
Ball mill (coal crusher) 1000 2 TETV IC 0151
Vapour fan 1000, 1500
Boiler feed pump (BFP) 1500, 3000 3 CACA IC 0161
Condensate pump 1000, 1500 4 CACW ICW 37A 81 01
Circulating water pump (CW pump) 375,429,500 ICW 37A 9 1