M1DK-80A Pulse-Triggered SCR Power Module: Trigger Wiring, Sizing and Commissioning

The M1DK-80A, also sold as SSR-80DV or BSSR-80DV, is a single-phase pulse-triggered SCR power module. It is not a DC-input solid state relay: it is triggered by the phase-angle pulse of an SCR heating controller such as the SCR-100 / ZKG-2000, which gives stepless heating power rather than on/off switching. Full ratings are on the M1DK / SSR-DV product page.

1. Specification

Parameter	Specification
Series	SSR-DV / M1DK (also known as BSSR-DV)
Models	SSR-25DV, 40DV, 60DV, 80DV, 100DV
Rated current	25A / 40A / 60A / 80A / 100A
Load voltage	24–250VAC, single-phase resistive
Control method	Pulse signal trigger
Trigger terminals	G / T1
Compatible controllers	ZKG, ZKC, ZKD SCR controllers
Isolation	≥100MΩ at 500VDC; dielectric strength over 4kV
Protection	Over-heat protection circuit at 120°C
Standards	EN60947-4-3, EN60950
Mounting	Bolt mount, transparent protective housing

2. Pulse trigger versus DC input

Parameter	Specification
M1DK / SSR-DV	Trigger pulse from an SCR controller on G and T1. Output voltage is continuously variable, so heating power is modulated smoothly.
SSR-DA	3–32VDC on/off control. The load is fully on or fully off; average power is set by duty cycle.

The two are not interchangeable. Feeding a DC level into a DV module, or a trigger pulse into a DA relay, will leave the heater dead or uncontrolled.

3. Wiring

• Connect the controller trigger output to the module G terminal and the trigger return to T1.
• Connect live to the module input terminal and the heater to the output terminal; neutral returns directly to the supply.
• Keep trigger wiring short, twisted and routed away from the load cables — a phase-angle stage is sensitive to induced noise.
• Fit upstream short-circuit protection sized for the module rating; semiconductor fuses are preferred where available.

4. Sizing and cooling

• Size at roughly twice the steady-state load current: an 80A module suits loads of about 35–40 A continuous.
• Budget 1 to 1.5 W of dissipation per ampere and fit a matched heat sink with thermal paste.
• Use forced-air cooling above roughly 40 A continuous, or where several modules share one cabinet.
• The 120°C over-heat protection circuit is a last-resort protection, not a substitute for correct thermal design.

5. Fault finding

Parameter	Specification
No heating, controller shows output	Trigger wiring reversed or open on G / T1; verify continuity and polarity at both ends.
Heating always at full power	Module SCR failed short, or the trigger is permanently held. Isolate and test with the controller output disconnected.
Output unstable or flickering	Trigger cable picking up noise from the load wiring; reroute and separate.
Module trips off after some minutes	Over-heat protection at 120°C is operating — heat sink undersized, dry mount, or blocked airflow.

6. FAQ

Which controller drives the M1DK?

Any ZKG, ZKC or ZKD style SCR heating controller, including the SCR-100 / ZKG-2000 panel unit.

Can I use a PID temperature controller instead?

Yes, if it has an SCR trigger output. Otherwise use a 4–20mA output controller with a BDTY SCR power regulator.

Is M1DK the same as BSSR-DV?

Yes — the same module is sold under the M1DK, SSR-DV and BSSR-DV names in different markets.

What load types are allowed?

Single-phase resistive heating loads. Contact us before applying it to transformers or other inductive loads.

Application review and quotations: sales@strong-ele.com.