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China MSQ Series Current Transformer - Reliable Suppliers & Quality Factory Equipment for Power Monitoring
Product Overview
A CT uses electromagnetic induction and is made up of two windings: a main winding with a few turns connected in series to a high-current circuit and a secondary winding with numerous turns connected to safety or measurement devices. While the secondary winding, which is typically tuned to 5A or 1A for the majority of industrial applications, receives very little current, the main winding receives a lot. This proportionality, also known as the transformation ratio, protects workers and equipment from dangerous voltages while enabling precise current monitoring.
CTs need enough insulation to maintain a high voltage between windings, linearity to reduce measuring error, and high precision for energy metering. The secondary winding should never be left open circuit while utilizing a CT. This is due to the possibility that an open circuit may create extremely high voltages, which could harm electrical equipment. Finally, current transformers are crucial to the dependability, effectiveness, and safety of contemporary electrical systems because they allow for more exact current monitoring and problem identification.
CTs need enough insulation to maintain a high voltage between windings, linearity to reduce measuring error, and high precision for energy metering. The secondary winding should never be left open circuit while utilizing a CT. This is due to the possibility that an open circuit may create extremely high voltages, which could harm electrical equipment. Finally, current transformers are crucial to the dependability, effectiveness, and safety of contemporary electrical systems because they allow for more exact current monitoring and problem identification.
- ⚡ Electromagnetic Induction: Dual-winding design with primary high-current and secondary low-current windings.
- 🎯 Standard Output: Secondary winding typically tuned to 5A or 1A for industrial applications.
- 🛡️ Safety First: High insulation between windings protects workers and equipment from dangerous voltages.
- 📐 High Precision: Excellent linearity minimizes measurement error for accurate energy metering.
- ⚠️ Important: Secondary winding must never be left open-circuit to prevent dangerously high voltages.
Technical Parameters
Dimensional Reference (mm)
| Type | A | B | C | D | E | F | G |
|---|---|---|---|---|---|---|---|
| MSQ-30 | 60 | 36 | 68 | 16 | 60 | 30 | 30 |
| MSQ-40 | 75 | 40 | 82 | 16 | 60 | 30 | 40 |
| MSQ-60 | 101 | 39 | 110 | 16 | 60 | 30 | 60 |
| MSQ-80 | 124 | 40 | 102 | 16 | 60 | 30 | 80 |
| MSQ-100 | 170 | 40 | 120 | 16 | 60 | 30 | 100 |
| MSQ-120 | 165 | 50 | 135 | 16 | 60 | 30 | 120 |
Model Specifications & Rated Parameters
| Picture | Type | Rated Current | Rated Burden (VA) Class: 0.5 |
Rated Burden (VA) Class: 1.0 |
Weight (kg) |
|---|---|---|---|---|---|
|
MSQ-30 Bar: 30×10mm Conductor: Φ20mm |
30/5A | 5 | 5 | 0.30 |
| 60/5A | |||||
| 80/5A | |||||
| 100/5A | |||||
| 200/5A | |||||
| 300/5A | |||||
|
MSQ-40 Bar: 40×10mm Conductor: Φ30mm |
100/5A | 2.5 | 2.5 | 0.38 |
| 200/5A | 5 | 5–10 | |||
| 300/5A | 5–10 | 5–10 | |||
| 400/5A | 5–10 | 5–10 | |||
| 500/5A | 5–10 | 5–10 | |||
|
MSQ-60 Bar: 60×20mm Conductor: Φ40mm |
300/5A | 5 | 5 | 0.60 |
| 400/5A | 5–10 | 5–10 | |||
| 500/5A | 5–10 | 5–10 | |||
| 600/5A | 10–15 | 10–15 | |||
| 800/5A | 10–15 | 10–15 | |||
| 1000/5A | 15 | 15 | |||
|
MSQ-80 Bar: 82×30mm Conductor: Φ80mm |
750/5A | 15 | 15 | 0.75 |
| 800/5A | 0.82 | ||||
| 1000/5A | 0.89 | ||||
| 1200/5A | 0.99 | ||||
| 1500/5A | 1.02 | ||||
|
MSQ-100 Bar: 105×30mm Conductor: Φ60mm |
1500/5A | 15 | 15 | 0.80 |
| 1600/5A | 0.80 | ||||
| 2000/5A | 0.94 | ||||
| 2500/5A | 1.10 | ||||
| 3000/5A | 1.16 | ||||
|
MSQ-120 Bar: 125×57mm or 125×10mm Conductor: Φ60mm |
1500/5A | 15 | 15 | 1.00 |
| 2000/5A | 1.15 | ||||
| 2500/5A | 1.45 | ||||
| 3000/5A | 1.60 | ||||
| 4000/5A | 1.90 | ||||
| 5000/5A | 2.20 |
Frequently Asked Questions (FAQ)
Q
What is the working principle of the MSQ series current transformer?
The MSQ series current transformer operates on the principle of electromagnetic induction. It consists of a primary winding (few turns, connected in series with the high-current circuit) and a secondary winding (many turns, connected to measuring or protection devices). The ratio of primary to secondary current is known as the transformation ratio, which allows safe and accurate monitoring of high currents.
Q
What is the standard secondary output current for the MSQ series CTs?
The MSQ series current transformers are standardized with a secondary output of 5A, which is the most common rating for industrial applications. This allows direct connection to standard protection relays, energy meters, and other measurement instruments.
Q
Why should the secondary winding of a CT never be left open-circuit?
If the secondary winding is left open-circuit while the primary carries current, the magnetic flux in the core will not be balanced by a secondary current. This causes the core to saturate and generates extremely high voltages across the secondary terminals, which can damage the insulation, destroy connected equipment, and pose a serious safety hazard to personnel. Always ensure the secondary is connected to a load or short-circuited when not in use.
Q
What accuracy classes are available for the MSQ series current transformers?
The MSQ series current transformers are available in Class 0.5 and Class 1.0 accuracy ratings. Class 0.5 is suitable for precision energy metering applications, while Class 1.0 is commonly used for general industrial measurement and protection purposes. Both classes have defined rated burden (VA) values depending on the model and rated current.
Q
How do I select the correct MSQ model for my application?
Model selection should be based on three key factors: (1) Primary rated current — choose a model whose rated current range covers your application's maximum current; (2) Conductor/busbar size — ensure the window opening (conductor diameter or busbar dimensions) of the CT matches your cable or busbar; (3) Rated burden — confirm the VA rating is sufficient for the connected measuring instruments. Refer to the technical parameters table for detailed specifications of each MSQ model.
Q
What is the largest rated current supported by the MSQ series?
The largest rated current in the MSQ series is 5000/5A, available in the MSQ-120 model. This model supports a busbar size of 125×57mm or 125×10mm with a conductor opening of Φ60mm, and has a weight of 2.20 kg. It is designed for high-capacity industrial power distribution systems requiring accurate current measurement at very high current levels.