HID Flip Boxes
HID flip boxes (also called relay switchboxes or alternating light controllers) allow one ballast to power two HPS or MH fixtures in an alternating sequence rather than running a single fixture continuously. The flip box switches the ballast output between two connected fixtures on a set timer interval -- typically alternating every 12 hours to match the lights-on period. This effectively doubles the number of light footprints operated per ballast, at the cost of each footprint receiving half the continuous light period rather than the full period. Flip boxes were used primarily in perpetual harvest operations to operate separate vegetative and flowering zones from a single ballast inventory.
Current Applications
Flip box technology was developed for HID ballast systems where ballast cost was a significant fraction of overall equipment investment. As LED grow lights have replaced HID in most new installations, flip box demand has declined -- LED fixtures operate continuously at a fixed wattage without the warm-up and cool-down cycling that made HID switching require specialized relay hardware. For existing HID operations or growers maintaining HID systems, flip boxes remain practical for running separate veg/flower zones from one ballast. For current flip box product availability, browse HID lighting controllers and complete grow light kits, or call 888-815-9763.
Electrical Considerations
Flip boxes must be rated for the ballast wattage and voltage they are switching -- a 1000W 240V ballast requires a flip box rated for that load. The relay mechanism in the flip box handles the repetitive switching cycles and must be sized appropriately for long-term reliability. Browse all grow lights or see timer and controller accessories. Fast shipping.
Flip Boxes FAQ
What is a flip box and how does it work?
A flip box is an electrical relay device that connects one HID ballast to two separate fixtures and alternates which fixture receives power on a set timer cycle. When the timer triggers, the relay switches the ballast output from Fixture A to Fixture B -- Fixture A powers down while Fixture B starts up. HPS lamps require a re-strike warm-up period of 3-5 minutes after switching before reaching full output, so the switching event is typically programmed to occur when the lights-on period begins (starting the new fixture on time while the previous one completes its cycle) rather than mid-period. The result is that two light footprints operate from one ballast investment at half the light hours per footprint per day.
Is a flip box a good setup for a perpetual harvest?
A flip box can support a perpetual harvest setup in an HID-equipped facility by allowing the same ballast to light a vegetative zone on one 12-hour period and a flowering zone on the other 12-hour period. The practical limitation is that each zone gets the light period it is scheduled for, but the plants in both zones must be on the same 12-hour offset schedule driven by the single ballast. For setups where veg and flower zones have different light schedule requirements (different start times, or veg at 18 hours rather than 12), a flip box does not provide the independent schedule control that a second ballast or independent zone lighting would. For LED-based setups, independent 0-10V dimming controllers per zone provide more flexible management than flip box technology.
What wattage flip box do I need?
Select a flip box rated at or above the wattage and voltage of the ballast it will switch. For a 1000W 240V ballast, use a flip box rated for 1000W or greater at 240V -- undersized relays will fail prematurely or create a fire hazard. Verify both wattage rating and voltage rating when selecting a flip box. The flip box relay must handle the inrush current of a starting HID lamp, which can be 2-3 times the steady-state current for the first few seconds of the start cycle -- relay ratings that specify surge or inrush capacity are more reliable than those rated only for steady-state current. Contact 888-815-9763 for specific product recommendations for your ballast configuration.