Combiner Box Frequently Asked Questions (FAQs)

  1. What is the difference between a "Standard" and a "Smart" combiner?

    DST’s "Standard" combiners do not have any I/O to measure string current and voltage. They are only meant to combine.

  2. How many strings can DST combine in one enclosure?

    DST is certified to provide up to 32 strings per enclosure.

  3. Can I order only the number of strings I require per my design?

    Yes, DST Controls can provide just the number of strings you require without any additional charges. We do not require you to purchase a standard number of strings.

  4. Can DST provide multiple combiners in one enclosure?

    Yes, DST can provide any number of combiners in one enclosure up to 32 strings per enclosure.

  5. What type of string input connectors does DST provide?

    As an option DST can provide cable glands, Tyco connectors, or MC style connectors. You can also specify side or bottom inputs.

  6. What type of combiner output fittings does DST provide?

    As an option DST can provide Type 4 conduit hubs. Please specify when placing an order.

  7. Why does DST provide metal enclosures as a standard?

    DST is one of the largest users of quality Rittal enclosures west of the Mississippi. There is not a lot of difference between the pricing of our metal enclosures versus poly carbonate or fiberglass. The metal enclosures are more secure and are lighter in color to reduce heat absorption.

  8. Are fuses included in my price?

    Yes, fuses are included. They must be specified when placing an order.

  9. What technology does DST use to measure string current?

    DST can provide three different technologies for Smart String monitoring. The most accurate (0.5%) uses our tried and true current shunt technology using military grade current shunts. The second most accurate (0.5% to 1.0%) uses our latest pulse reset technology developed in cooperation with a leading manufacturer of power products. The third most accurate (1% to 2%) uses Hall Effect from NOARK Electrics.

  10. Can DST provide an integral DC PV rated disconnect or circuit breaker?

    Yes, DST has researched and uses the finest DC rated disconnects and breakers currently on the market. Our breakers and disconnects comply with even the upcoming new requirements by UL.

  11. Can DST provide a transient voltage suppressor in each combiner?

    Yes, DST can provide the latest in PV approved safety devices.

  12. What communication protocol does DST use in their "Smart" combiners?

    DST can provide either RS485 Modbus RTU or Modbus TCP/IP which are used by the majority of solar monitoring companies and solar monitoring software packages.

  13. What monitoring company software will DST’s "Smart" combiners work with?

    All. The near future objective of the monitoring companies is to only provide the backend services. The hardware is to become generic. DST is positioned themselves for this transition.

  14. Can DST provide a 24VDC power supply to operate the "Smart" features?

    Yes, DST can provide many options for powering the Smart features to include a 100-1000V DC input power supply that is powered directly from the combiner and provides a regulated 24VDC output or any other input style. Please contact DST to discuss your 24VDC requirements.

  15. How do I size the 24VDC power supply needed for the "Smart" combiners?

    The 24VDC power supply is dependent upon your system design and the number of "Smart" modules per enclosure. Please contact DST to discuss your requirements.

  16. Does DST provide any discounts for quantity orders?

    Yes, DST can provide discounts based on large single or blanket orders. Please contact us to discuss this in further detail since our current pricing for our quality products is already cost competitive.