Jump Start 140W Commercial Seedling Heat Mat Modular Add-on - 60" x 21"

No. The MTMDA is an expansion unit only and must be connected downstream from a primary commercial mat. The MTMDU serves as the power and control entry point for the entire chain, connecting to the required digital thermostat. An MTMDA cannot be plugged directly into a thermostat or wall outlet on its own.

Up to four MTMDA add-on units can be daisy-chained to one MTMDU primary mat, for a total of five mats in the system. Each unit connects to the one before it via the waterproof daisy-chain connectors — the MTMDU always starts the chain, followed by up to four MTMDAs in sequence.

Each mat in the chain — both the MTMDU and each MTMDA — draws 140W, so a fully loaded five-mat configuration totals 700W. Verify that your thermostat and wall circuit are rated to handle the combined load before connecting all five units. The Jump Start Digital Temperature Controller is rated for 1000W, which covers the full five-mat setup.

The entire chain is controlled by a single digital thermostat connected to the primary mat — so all mats in the chain heat together based on the same temperature set point. There is no independent zone control per mat. All units in the chain respond simultaneously to the thermostat's probe reading and set temperature.

Yes. The MTMDA is dimensionally identical to the MTMDU at 60" × 21" and draws the same 140W at 120V. The only functional difference is the connection type — the MTMDU connects to a thermostat to start the chain, while the MTMDA connects to an MTMDU or another MTMDA to extend it.

MTMDA units can connect to each other in series — they do not each need to plug directly into the MTMDU. The chain runs MTMDU → MTMDA → MTMDA → MTMDA → MTMDA, with each unit passing power to the next. Only the first unit in the chain must be the MTMDU, which is the only model that connects to the thermostat.