DC Power Supply Characteristics and Wiring

Overview

This section provides the characteristics and the wiring diagrams of the DC power supply.

DC Power Supply Voltage Range

If the specified voltage range is not maintained, outputs may not switch as expected. Use appropriate safety interlocks and voltage monitoring circuits.

DANGER
	FIRE HAZARD Use only the correct wire sizes for the maximum current capacity of the I/O channels and power supplies. For relay output (2 A) wiring, use conductors of at least 0.5 mm² (AWG 20) with a temperature rating of at least 80 °C (176 °F). For common conductors of relay output wiring (7 A), or relay output wiring greater than 2 A, use conductors of at least 1.0 mm² (AWG 16) with a temperature rating of at least 80 °C (176 °F). Failure to follow these instructions will result in death or serious injury.

DANGER

FIRE HAZARD

Use only the correct wire sizes for the maximum current capacity of the I/O channels and power supplies.
For relay output (2 A) wiring, use conductors of at least 0.5 mm² (AWG 20) with a temperature rating of at least 80 °C (176 °F).
For common conductors of relay output wiring (7 A), or relay output wiring greater than 2 A, use conductors of at least 1.0 mm² (AWG 16) with a temperature rating of at least 80 °C (176 °F).

Failure to follow these instructions will result in death or serious injury.

WARNING
	UNINTENDED EQUIPMENT OPERATION Do not exceed any of the rated values specified in the environmental and electrical characteristics tables. Failure to follow these instructions can result in death, serious injury, or equipment damage.

DC Power Supply Requirements

The M241 Logic Controller and the associated I/O (TM2, TM3, and embedded I/O) require power supplies with a nominal voltage of 24 Vdc. The 24 Vdc power supplies must be rated Safety Extra Low Voltage (SELV) or Protective Extra Low Voltage (PELV) according to IEC 61140. These power supplies are isolated between the electrical input and output circuits of the power supply.

WARNING
	POTENTIAL OF OVERHEATING AND FIRE Do not connect the equipment directly to line voltage. Use only isolating PELV power supplies and circuits to supply power to the equipment¹. Failure to follow these instructions can result in death, serious injury, or equipment damage.

¹ For compliance to UL (Underwriters Laboratories) requirements, the power supply must also conform to the various criteria of NEC Class 2, and be inherently current limited to a maximum power output availability of less than 100 VA (approximately 4 A at nominal voltage), or not inherently limited but with an additional protection device such as a circuit breaker or fuse meeting the requirements of clause 9.4 Limited-energy circuit of UL 61010-1. In all cases, the current limit should never exceed that of the electric characteristics and wiring diagrams for the equipment described in the present documentation. In all cases, the power supply must be grounded, and you must separate Class 2 circuits from other circuits. If the indicated rating of the electrical characteristics or wiring diagrams are greater than the specified current limit, multiple Class 2 power supplies may be used.

Controller DC Characteristics

The following table shows the DC power supply characteristics required for the controller:

Characteristic		Value
Rated voltage		24 Vdc
Power supply voltage range		20.4...28.8 Vdc
Power interruption time		1 ms at 24 Vdc
Maximum inrush current		50 A
Power consumption		32.6 W	max. 40.4 W⁽¹⁾
Isolation	between DC power supply and internal logic	Not isolated
Isolation	between DC power supply and protective earth ground (PE)	500 Vac
(1) Controller + 7 TM3 expansion modules

Power interruption

The TM241C••24T / TM241C•40T / TM241C••24U and TM241C•40U must be supplied by an external 24 V power supply equipment. During power interruptions, the M241 Logic Controller, associated to the suitable power supply, is able to continue normal operation for a minimum of 10 ms as specified by IEC standards.

When planning the management of the power supplied to the controller, you must consider the power interruption duration due to the fast cycle time of the controller.

There could potentially be many scans of the logic and consequential updates to the I/O image table during the power interruption, while there is no external power supplied to the inputs, the outputs or both depending on the power system architecture and power interruption circumstances.

WARNING
	UNINTENDED EQUIPMENT OPERATION Individually monitor each source of power used in the controller system including input power supplies, output power supplies and the power supply to the controller to allow appropriate system shutdown during power system interruptions. The inputs monitoring each of the power supply sources must be unfiltered inputs. Failure to follow these instructions can result in death, serious injury, or equipment damage.

WARNING

UNINTENDED EQUIPMENT OPERATION

Individually monitor each source of power used in the controller system including input power supplies, output power supplies and the power supply to the controller to allow appropriate system shutdown during power system interruptions.
The inputs monitoring each of the power supply sources must be unfiltered inputs.

Failure to follow these instructions can result in death, serious injury, or equipment damage.

DC Power Supply Wiring Diagram

The following figure shows the power supply terminal block removal procedure:

The following figure shows the wiring of the DC power supply:

* Type T fuse

For more information, refer to the 5.08 pitch Rules for Removable Screw Terminal block.