TM3DQ8T

The Schneider Electric TM3DQ8T, also cataloged as the TM3DQ8T discrete output module, provides eight 24 VDC transistor outputs with positive logic (PNP/source) for Modicon M221, M241, M251 and M262 controllers. It switches external loads through removable screw terminals and receives power and communication through the TM3 expansion bus.

Hardware Specifications

Parameter	Specification
Model	TM3DQ8T
Brand	Schneider Electric
Product Series	Modicon TM3
Product Type	Discrete Output Module
Number of Outputs	8 transistor outputs
Output Logic	Positive logic (PNP/source)
Rated Output Voltage	24 VDC
Output Current	50 mA per transistor output
Maximum Turn-On Time	450 us
Maximum Turn-Off Time	450 us
Maximum Leakage Current	0.1 mA
Maximum Voltage Drop	Less than 0.4 V
Isolation Between Outputs and Internal Logic/Bus	500 VAC
Isolation Between Outputs	Not isolated
Bus Current Consumption	20 mA at 5 VDC; 10 mA at 24 VDC (specified values)
Electrical Connection	Removable screw terminal block, 5.08 mm pitch
Maximum Cable Distance	30 m with unshielded cable
Local Indication	1 green LED per output channel
Compatible Controllers	Modicon M221, M241, M251, M262
Mounting	TH35-7.5 or TH35-15 DIN rail; panel mounting with fixing kit
Protection Rating	IP20
Dimensions (W x D x H)	27.4 x 84.6 x 90 mm
Weight	0.76 kg
Operating Temperature	-10 to 35 deg C, vertical; -10 to 55 deg C, horizontal
Storage Temperature	-25 to 70 deg C
Relative Humidity	10-95%, non-condensing
Operating Altitude	Up to 2000 m
Pollution Degree	2
Shock Resistance	15 gn, 11 ms
Standards	IEC 61131-2
Certifications	CE, cULus, UKCA, RCM, EAC, cULus HazLoc
Country of Origin	Taiwan (TW)
GTIN	3606480611469
Lifecycle Carbon Footprint	62 kg CO2 eq.

PNP Output Switching and Bus Isolation

The TM3DQ8T uses source-type transistor outputs to switch positive 24 VDC to connected loads. Each output has a specified maximum current of 50 mA, with a maximum voltage drop below 0.4 V and maximum leakage current of 0.1 mA.

The 500 VAC isolation specification applies between the outputs and the internal logic/bus. The eight output channels are not isolated from one another. External loads must be selected according to the output current rating and the electrical characteristics of the connected device.

The module connects to compatible Modicon controllers through the TM3 expansion bus. Output wiring terminates at the removable screw terminal block, while individual green LEDs indicate output status.

Frequently Asked Questions (FAQ)

Q: Can the TM3DQ8T directly drive a variable speed drive?

A: It can control a drive equipped with a compatible current or voltage input, as specified by the manufacturer. Verify the drive input type, switching requirements and electrical interface before connection. The transistor output is not a substitute for a drive power circuit.

Q: Are the eight output channels galvanically isolated from each other?

A: No. The manufacturer specifies 500 VAC isolation between the outputs and the internal logic/bus, but no isolation between individual output channels.

Q: What installation conditions affect the module's operating temperature rating?

A: The specified range is -10 to 35 deg C for vertical installation and -10 to 55 deg C for horizontal installation. Maintain the applicable orientation, enclosure ventilation and wiring clearances during installation.

Field Installation Guidelines

1. Mounting: Install the module on a compatible TH35-7.5 or TH35-15 DIN rail, or use the specified panel mounting kit. Engage the TM3 interlocking mechanism and expansion bus connector correctly.
2. Power and bus connection: Verify controller compatibility and ensure the expansion bus connector is fully seated before energizing the system.
3. Output wiring: Connect field loads to the removable screw terminals according to the PNP/source output arrangement. Use conductors within the specified 0.2-2.5 mm2 range.
4. Load verification: Confirm that each connected load is compatible with 24 VDC operation and the 50 mA maximum output current. Use an appropriate interface device when the load exceeds the output rating.
5. Cable routing: Keep output wiring separated from high-voltage switching and motor power cables where practicable. The specified maximum cable distance for unshielded transistor-output wiring is 30 m.
6. Grounding and shielding: Follow the controller and machine manufacturer's grounding instructions. Where shielded field cables are used, terminate shields according to the installation design and EMC requirements.
7. Commissioning: Verify terminal tightness, field wiring polarity, controller I/O configuration and channel LED status. Test each output with its connected load before returning the machine to service.

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