Product Category : Boxes
Speed-O-Controls Pvt. Ltd offers Resistance boxes are used to add resistance in to an electric motor circuit for modifying the performance characteristic of slipping electric motors of EOT cranes, rubber mills, steel rolling mills, cement mills, power plants, conveyors, coke oven, blowers etc. For speed control and developing starting torque with low starting currents. They arc also used as Dynamic breaking resistor for V.V.V.F. A.C. Drives, electric loading of ac alternators, dc generators and dynamometers. Resistors are designed to meet requirements of both A.C. & D.C. Applications.
The basic types of resistors are:
Stainless Steel wire resistors and
Punched Steel Resistors.
The system of cooling the resistors is of two types
Air cooled type
Oil cooled type
The key features of the Resistance boxes are:
Enclosure material - Galvanized Sheet Steel [Hotdip]
Mounting - Floor mounting
Degree of Protection -IP-21/22/23.
Current Rating [SS Grid] - 7 to 400 Amps Continues.
Current Rating [PS Grid] - 7 to 800 Amps, Continues.
Cooling -Air Cooled/Oil Cooled
Temperature rise - 225o/250°/375°C.
Cable Entry- Bottom Entry
Current rating chart for punched grid resistors for 375°C temperature rise
| Rated Ohms
|
Grid Type |
Current limits intermittant duty [Amps]
|
| 25% ED |
40% ED |
60% ED |
100% ED |
| 0.01 |
PS10 |
390 |
325 |
280 |
234 |
| 0.022 |
PS22 |
265 |
220 |
190 |
158 |
| 0.032 |
PS32 |
220 |
182 |
153 |
131 |
| 0.046 |
PS46 |
185 |
151 |
130 |
110 |
| 0.068 |
PS68 |
152 |
126 |
110 |
90 |
| 0.1 |
PS 100 |
125 |
103 |
88 |
74 |
| 0.15 |
PS150 |
101 |
84 |
72 |
61 |
| 0.22 |
PS220 |
83 |
70 |
59 |
50 |
| 0.3 |
PS300 |
82 |
59 |
50 |
43 |
| 0.46 |
PS460 |
58 |
48 |
40 |
35 |
| 0.72 |
PS720 |
47 |
39 |
33 |
28 |
| 1 |
PS1000 |
40 |
33 |
28 |
24 |
| 1.5 |
PS1500 |
32 |
27 |
23 |
19 |
| 2.5 |
PS2500 |
25 |
21 |
18 |
15 |
| 4.5 |
PS4500 |
15 |
13 |
11 |
8 |
|
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