FAQ
1. What is the difference between DM-20 and DM-30 current transformers?
The published 5A-output selection table lists DM-20 ratios from 15/5A to 300/5A and DM-30 ratios from 100/5A to 300/5A. Rated burden also varies by model and ratio. Choose the model according to your primary current, required burden, conductor dimensions and available installation space.
2. How do I choose the current ratio and secondary output for a DM current transformer?
Select the primary current rating according to the normal operating current and maximum expected load. The secondary output must match your meter’s input, either 1A or 5A. The DM series lists both output options, but the published ratio tables cover 5A versions. Please confirm the ratio, accuracy and burden of your required 1A version before ordering.
3. What accuracy class and measuring range do DM current transformers offer?
The published DM-20 and DM-30 selection tables specify Class 1.0, while the series lists a measuring range of 5% to 120% of rated primary current and a frequency of 50/60Hz. Accuracy should be assessed under the specified current and burden conditions. For applications requiring accurate measurement at low current, please provide your operating range for technical confirmation.
4. How do I select the rated burden for a DM current transformer?
Consider the combined burden of the connected meter and secondary wiring. The published 5A-output tables list rated burdens from 1.5VA to 3.75VA, depending on the model and ratio. Select a version whose specified burden conditions suit your complete secondary circuit. Provide the meter burden, cable length and conductor cross-section to help confirm compatibility.
5. Can DM current transformers be mounted on a DIN rail?
Yes. The DM series supports DIN mounting and features a compact design with a hinged terminal cover. Before ordering, check the model’s mounting drawing, compatible rail specification, conductor opening and clearance for wiring. Confirming these dimensions helps ensure the transformer fits your electrical panel.
