Dold relayCommon types include safety relays and solid-state relays. The wiring logic of different types has similarities and differences. Among them, the wiring of safety relays needs to pay extra attention to the reset circuit, while solid-state relays need to distinguish between AC and DC loads. The following are general and exclusive wiring methods based on their terminal identification, with clear steps and suitable for most mainstream models:
Preparation before universal wiring
Cut off the power first to avoid electric shock. Re check the relay model to match the circuit voltage and load current. For example, safety relays are commonly powered by 24V DC, and it is necessary to confirm the compatibility requirements between the power supply and terminals A1 and A2.
Use the product manual to clarify the meaning of terminals, such as A1/A2 being universal power terminals, S series mostly being control input terminals, and S33/S34 often corresponding to reset terminals, to avoid connecting the wrong circuit.
Safety relays (such as mainstream models OA5611, OA5622, etc.)
Power circuit wiring: This is the basic circuit for the operation of the relay. Terminal A1 is connected to the positive pole of a 24V DC power supply, and terminal A2 is connected to the negative pole of the power supply. If the wiring is reversed, it will cause the relay to fail to start, and it is necessary to ensure that the power supply voltage is stable to avoid fluctuations and damage to the coil.
Control input circuit wiring: This circuit is used to connect the signal that triggers the action of the relay. Connect the emergency stop button, safety door contacts, and other switch components between terminals S11 and S12, and S11 and S22, respectively. The safety relay will only enter normal working state when both sets of circuits meet the preset switch conditions.
Reset circuit wiring: Reset must meet dual conditions. On the one hand, reset condition components such as reset buttons should be connected between terminals S33 and 634; On the other hand, it is necessary to ensure that the auxiliary reset condition between terminals Y1 and Y2 is met, and both are met simultaneously, in order for the relay to complete the reset and restore normal function.
Output circuit wiring: Find the output contact terminal of the relay (usually labeled as output related identification) and connect it to the control circuit of the device. For example, connecting the normally open output contacts in series in the starting control circuit of the device, when the relay is activated, the contacts close and the device control signal is connected.
Solid state Dold relay
Control input terminal wiring: Solid state relay input terminals are often marked with "+" and "-". Connect the positive pole of the control signal source (such as PLC output terminal) to the input terminal "+" and the negative pole to the input terminal "-". The control signal is generally a direct current voltage, which needs to be matched with the rated control voltage of the relay to avoid burning the input components due to high voltage.
Load output terminal wiring: The output terminal is usually labeled with L/A, T/B, and other identifiers. If the load is an AC device (such as an AC motor), connect the live wire of the power supply to the output terminal L/A, connect one end of the load to the output terminal T/B, and connect the other end of the load to the neutral wire of the power supply; If it is a DC load, the output terminal and power supply should be connected according to the polarity requirements of the load. Some AC output solid-state relays do not need to distinguish the output polarity.
Auxiliary protection wiring: If used in high-power load scenarios, heat sinks can be used for wiring, while ensuring that the cross-sectional area of the output terminal wire matches the load current to prevent long-term heat generation and circuit aging; If the equipment has grounding requirements, the relay grounding terminal must be reliably grounded to avoid potential leakage hazards.
Test after wiring
After the wiring is completed, first use a multimeter to check whether each circuit is conductive and whether there is a short circuit. Re power on the test and observe whether the relay is smoothly engaged and released, whether the load equipment can start and stop normally according to the control logic. If any abnormalities occur, immediately cut off the power and check whether the terminal wiring is loose or incorrectly connected.