Inductive reactors for the start-up of asynchronous three-phase motors
Limitation of strain on the network and the motor at start-up
Start-up with stator reactance consists in the insertion of three reactors in the line capable of causing a suitable voltage drop at the motor terminals.
This type of start-up has the advantage of its great simplicity and the feature of an easily adjustable start-up, using the various models available.
The downside is that the rotor will impose a limit on the service provided by the motor (the number of start-ups per hour is equal to 4 or 5) and involves a low power factor at start-up.
Start-up with an auto-transformer is based on the same voltage reduction principle; however, auto-transformers are normally used with large machinery having low / medium-level voltages.
The table below provides indicative dimensions (mm) of the most common types of reactors that we have standardized.
TYPE |
HP motor |
A |
B |
C |
D |
E |
G |
Kg. |
RP0.1 |
2—3 |
120 |
57 |
115 |
100 |
46 |
67 |
2 |
RP0.2 |
4—6 |
150 |
78 |
147 |
125 |
56 |
82 |
4 |
RP0.3 |
7—10 |
150 |
93 |
147 |
125 |
71 |
97 |
5,4 |
RP0.4 |
11—15 |
150 |
93 |
147 |
125 |
71 |
97 |
5,8 |
RP0.5 |
16—22 |
180 |
100 |
180 |
150 |
76 |
106 |
7,4 |
RP1 |
23—29 |
180 |
100 |
185 |
150 |
76 |
108 |
8,4 |
RP1.5 |
30—37 |
180 |
106 |
195 |
150 |
86 |
130 |
10,9 |
RP2 |
40—50 |
240 |
120 |
235 |
200 |
90 |
130 |
16,8 |
RP2.2 |
50—60 |
240 |
132 |
240 |
200 |
100 |
142 |
20,5 |
RP2.5 |
60—70 |
300 |
130 |
290 |
250 |
92 |
130 |
23,8 |
RP3 |
80—100 |
300 |
140 |
290 |
250 |
102 |
166 |
31 |
RP3.5 |
110—120 |
300 |
150 |
300 |
250 |
112 |
190 |
37 |
RP4 |
130—150 |
300 |
160 |
300 |
250 |
122 |
220 |
42 |
RP5 |
160—180 |
360 |
175 |
355 |
325 |
140 |
220 |
55 |
RP6 |
200—220 |
360 |
190 |
350 |
325 |
155 |
240 |
68 |
RP7 |
250—280 |
360 |
210 |
350 |
325 |
185 |
290 |
89 |
NOTES: SIZES ARE PURELY INDICATIVE AND MAY BE MODIFIED WITHOUT PRIOR NOTICE