- Stock: 66
- Model: Relé-10A
Type:
10A
10A Omron
SSR-40DA solid-state relay for controlling an AC load from a 3 to 32 V DC signal. The unit is marked for a 24 to 380 V AC output and a nominal current of 40 A.
Confirmed unit data
| Type | SSR-40DA: DC control and AC load |
|---|---|
| Control input | 3–32 V DC |
| Output | 24–380 V AC |
| Marked current | 40 A nominal; this does not mean 40 A continuously without thermal design |
| Approximate dimensions | 62 × 45 × 24 mm; 48 mm mounting centres and 4.8 mm slot |
Nominal current and heat removal
The 40 A figure is the nominal current marked on the module, not a guarantee of continuous operation at that current. An SSR generates heat while conducting and its real capacity depends on the heat sink, thermal compound, ambient temperature, ventilation, duty cycle, load, wiring and mounting.
Because an exact traceable thermal curve is unavailable for this reference, we do not state a safe continuous current without a heat sink. Significant loads require a suitable heat sink, a thin layer of thermal compound, ventilation and ample margin below the working current. Check temperature under real operating conditions before considering the installation complete.
Terminals and load type
| Terminal | Function |
|---|---|
| 1 and 2 | AC output, wired in series with line and the load |
| 3 (+) | Positive 3–32 V DC control signal |
| 4 (−) | Negative control signal |
Its most natural application is a resistive AC load such as a mains-powered silicone heater. It cannot directly switch a 12/24 V DC bed or load. Motors, transformers, lamps and capacitive loads may have large inrush currents and require specific selection and protection.
Marlin, Klipper and RepRapFirmware use
The controller's heater output is used only to drive the SSR's DC input; the mains load has its own circuit and the temperature sensor remains connected to the controller.
- Marlin: retain thermal protection. Bang-bang control with
BED_LIMIT_SWITCHINGprovides spaced switching; usePIDTEMPBEDonly after confirming the relay accepts the resulting frequency and tuning the actual system. - Klipper: configure
heater_bedorheater_genericwith its sensor and limits, retainverify_heater, and select apwm_cycle_timecompatible with the SSR's real behaviour. - RepRapFirmware: define sensor, output, control and limit with
M308,M950,M307andM143. Do not automatically copy the frequency from another installation.
We do not specify a universal frequency because this unit's internal switching mode is not documented precisely enough. Prefer compatible slow cycles, validate its behaviour and do not assume fast MOSFET PWM.
Installation safety
This product may handle mains voltage. It must be installed by a qualified person, with power isolated and inside a closed enclosure, using protected terminals, suitable cable and terminals, protective earth and correctly rated circuit protection.
An SSR may leak a small current while off and may fail in the on state. It is neither a maintenance isolator nor the only safety device: add mechanical disconnection, overcurrent protection and an independent thermal cut-out that does not rely on firmware or the SSR.
This product is for you if
- You need to control a resistive AC load from a 3–32 V DC signal.
- You will size the heat sink, ventilation, wiring and protection with sufficient margin.
- You can test temperature and operation in the completed installation.
This product is not for you if
- Your load operates at 12 or 24 V DC.
- You expect 40 A continuously without thermal calculations or a heat sink.
- You require a reference with an officially documented current curve, leakage current and switching parameters.
If you prefer a 10 A alternative with manufacturer-documented thermal limits and zero-cross switching, see the Omron G3NB-210B-1. Its voltage and current conditions differ, so it must not be substituted without reviewing the installation.
