DITEK DTK-DF120S1 Series-Connected Surge Protective Device, 120VAC 20A, Deflector Series, UL 1449 Type 2

DITEK DTK-DF120S1 — Deflector Series series-connected 120 VAC surge protective device with a replaceable plug-in module, Form C dry contacts and an audible alarm.

DITEK states the connection outright: this is a series connected device, wired between the 120 VAC supply and the fire alarm or branch panel input rather than tapped in parallel, which is why it has a continuous current rating. At module end of life the red REPLACE LED lights and the alarm sounds.

• 120 VAC single phase, MCOV 150 V, 20 A continuous, 50/60 Hz
• Surge current 50,000 A; nominal discharge 10 kA; SCCR 10,000 A
• VPR 600 V line-ground, 700 V line-neutral, 1200 V neutral-ground
• UL 1283 EMI and RFI filtering to -35 dB, 100 kHz to 100 MHz
• Form C dry contacts and an 80 dB alarm at 1 ft, silenced 24 hours by a bypass switch
• Mechanical lugs for 12 AWG at 20 in.-lb; 3/4 in. and 1/2 in. NPT holes
• ABS enclosure 6.58 × 5.33 × 2.61 in., -4 to 140 °F; UL 1449 5th Ed. Type 2

Keep a spare DTK-DF120M: the base is unprotected without one. DTK-DF240S1 is the 240 VAC version, taking the DTK-DF240M at 300 V MCOV, and DTK-DF120S12 the twelve circuit enclosure, whose line-ground VPR is 700 V.