Bender has a range of current transformers for load currents (operating currents) and residual currents (RCM). Different designs cover a variety of installation situations and metrological requirements, and enable retrofitting.
Find Current Transformers!| Size (AWG/MCM) | THW/THHW/TW Insulation (In./mm) | TFN/THHN/TWWN Insulation (In./mm) | Uninsulated Conductors Range Min (In./mm) | Uninsulated Conductors Range Max (In./mm) |
|---|---|---|---|---|
| 24 AWG | 0.059 (1.5) | 0.088 (2.2) | 0.020 (0.5) | 0.024 (0.6) |
| 22 AWG | 0.066 (1.7) | 0.094 (2.4) | 0.025 (0.6) | 0.031 (0.8) |
| 20 AWG | 0.071 (1.8) | 0.101 (2.6) | 0.032 (0.8) | 0.038 (1.0) |
| 18 AWG | 0.084 (2.1) | 0.111 (2.8) | 0.040 (1.0) | 0.049 (1.2) |
| 16 AWG | 0.096 (2.4) | 0.124 (3.1) | 0.051 (1.3) | 0.060 (1.5) |
| 14 AWG | 0.111 (2.8) | 0.133 (3.4) | 0.064 (1.6) | 0.073 (1.9) |
| 12 AWG | 0.130 (3.3) | 0.152 (3.9) | 0.081 (2.1) | 0.095 (2.4) |
| 10 AWG | 0.164 (4.2) | 0.176 (4.5) | 0.102 (2.6) | 0.116 (2.9) |
| 8 AWG | 0.216 (5.5) | 0.236 (6.0) | 0.128 (3.3) | 0.146 (3.7) |
| 6 AWG | 0.254 (6.5) | 0.304 (7.7) | 0.162 (4.1) | 0.184 (4.7) |
| 4 AWG | 0.324 (8.2) | 0.352 (8.9) | 0.204 (5.2) | 0.232 (5.9) |
| 3 AWG | 0.352 (8.9) | 0.380 (9.7) | 0.229 (5.8) | 0.260 (6.6) |
| 2 AWG | 0.384 (9.8) | 0.420 (10.7) | 0.258 (6.6) | 0.292 (7.4) |
| 1 AWG | 0.446 (11.3) | 0.492 (12.5) | 0.289 (7.3) | 0.332 (8.4) |
| 1/0 | 0.486 (12.3) | 0.532 (13.5) | 0.325 (8.3) | 0.373 (9.5) |
| 2/0 | 0.532 (13.5) | 0.578 (14.7) | 0.365 (9.3) | 0.418 (10.6) |
| 3/0 | 0.584 (14.8) | 0.630 (16.0) | 0.410 (10.4) | 0.470 (11.9) |
| 4/0 | 0.642 (16.3) | 0.688 (17.5) | 0.460 (11.7) | 0.528 (13.4) |
| 250 MCM | 0.711 (18.1) | 0.765 (19.4) | 0.500 (12.7) | 0.575 (14.6) |
| 300 MCM | 0.766 (19.5) | 0.820 (20.8) | 0.548 (13.9) | 0.630 (16.0) |
| 350 MCM | 0.817 (20.8) | 0.871 (22.1) | 0.592 (15.0) | 0.681 (17.3) |
| 400 MCM | 0.864 (21.9) | 0.918 (23.3) | 0.633 (16.1) | 0.728 (18.5) |
| 500 MCM | 0.949 (24.1) | 1.003 (25.5) | 0.707 (18.0) | 0.813 (20.7) |
| 600 MCM | 1.051 (26.7) | 1.113 (28.3) | 0.775 (19.7) | 0.893 (22.7) |
| 700 MCM | 1.122 (28.5) | 1.184 (30.1) | 0.837 (21.3) | 0.964 (24.5) |
| 750 MCM | 1.156 (29.4) | 1.218 (30.9) | 0.866 (22.0) | 0.998 (25.3) |
| 800 MCM | 1.188 (30.2) | 1.250 (31.8) | 0.894 (22.7) | 1.031 (26.2) |
| 900 MCM | 1.252 (31.8) | 1.314 (33.4) | 0.949 (24.1) | 1.093 (27.8) |
| 1000 MCM | 1.310 (33.3) | 1.372 (34.8) | 1.000 (25.4) | 1.152 (29.3) |
| 1250 MCM | ---- | 1.539 (39.1) | 1.121 (28.5) | 1.289 (32.7) |
| 1500 MCM | ---- | 1.662 (42.2) | 1.228 (31.2) | 1.412 (35.9) |
| 1750 MCM | ---- | 1.776 (45.1) | 1.327 (33.7) | 1.526 (38.8) |
| 2000 MCM | ---- | 1.882 (47.8) | 1.419 (36.0) | 1.632 (41.5) |
There is no required time interval for calibration. However, we recommend performing an offset calibration if the CT has been moved (this calibration procedure only applies to the CTBC series). While not mandatory, testing your circuit every few months is a good practice to ensure proper operation and system health. Also, remember that the ground conductor should never pass through the CT!
