Omron C500 series rack mounted PLC

The installation manual (W132E13D) for Omron C500 series rack mounted PLC, revised in 1997, fully explains the system composition, rack/module/power/memory installation specifications, I/O wiring, environmental requirements, power design, noise protection, safety measures of this modular PLC, clarifies the CPU rack+extended I/O rack architecture, maximum 512 point I/O, supports AC100-240V/DC24V dual power supply, 5 types of I/O module shapes, and various special functional modules. It provides detailed wiring examples, fault protection, and consumables replacement processes, and is the official basis for equipment installation, electrical debugging, and maintenance.

System composition and architecture

C500 is a rack mounted card structure consisting of a CPU system and an expansion system.

CPU rack

Backboard: 3/5/6/8/9 slots available for selection

Core components: CPU unit, CPU power supply, I/O control unit, I/O unit

Expand I/O rack

Backboard: Expansion specific

Components: I/O interface unit, expansion power supply, I/O unit

Maximum configuration

Connect up to 3 expansion racks

Maximum I/O points: 512 points

memory

RAM package: Supports 16K/24K words, battery needs to be maintained during power failure

ROM package: equipped with EPROM chip, program is not lost in case of power failure

Module and power specifications

1. Power supply unit (key parameters)

Model Power Supply 5V Output I/O Available Current 24V Auxiliary Output

3G2A5-PS221-E AC100-240V 7A 5A 0.8A

3G2A5-PS223-E AC100-240V 12A 10A None

3G2A5-PS213-E DC24V 9A 5A None

3G2A5-PS222-E AC100-240V 7A 6.5A 0.8A

3G2A5-PS212-E DC24V 7A 6.5A None

2. Classification of I/O units

Appearance: 5 different structures A/B/C/D/E

Input: DC24V, AC100-120V, AC/DC universal TTL

Output: Relay, transistor, bidirectional thyristor

Special I/O: AD/DA, high-speed counting, position control PID、 Link unit

3. Module power consumption (typical value)

Input unit: 0.01~0.34A

Output unit: 0.1~0.46A

Special Unit: 0.3~1.4A

Installation and environmental requirements

Installation method

Must be installed vertically, with the CPU rack on top

Rack spacing: 70~120mm

Expansion cable: Single cable up to 2m in length, total length ≤ 12m

Environmental restrictions

Temperature: 0~55 ℃

Humidity: 10%~90% RH (no condensation)

Vibration: 10~55Hz, 0.5mm, 2G

Impact: 10G, 3 times

Wiring and noise resistance

The distance between strong current and I/O lines is ≥ 300mm

Shielded twisted pair cables must be used

Grounding resistance: ≤ 100 Ω, wire diameter ≥ 2mm ²

System wiring specifications

Power wiring

AC power supply: supports 100-120V/200-240V switching

Terminal torque: 1.2N · m

Circuit breakers must be installed

I/O wiring

Wire gauge: AWG22~18 (0.3~0.75mm ²)

Cold pressed terminals must be used and bare wires are prohibited

Terminal torque: maximum 8kg · cm

safety protection

Inductive load: parallel surge absorber/diode

Leakage current: Input/output with discharge resistor

Interlock: The forward and reverse rotation of the motor must be interlocked with external hardware

Power supply and power outage handling

Power failure response

Power outage ≤ 10ms: ignored

10-25ms: Possible shutdown

25ms: Stop output, automatically restart after recovery

Grounding requirements

Reasonable connection between LG and GR terminals enhances noise resistance

Grounding and strong current system are independent

Safety precautions

Mandatory Security

Power off operation: plugging and unplugging modules, wiring, and replacing accessories

Prohibit touching terminals with live electricity and disassembling modules

system security

Emergency stop requires external hard wiring

Key circuits provide dual safety mechanisms

Maintenance and consumables replacement

battery

Lifespan: 4 years (25 ℃)

Replace within one week after reporting the alarm

Replacement time: ≤ 5 minutes

fuse

Specification: 3A/250V (MF61NR)

Replacement requires power-off operation

relay

Electric lifespan: 300000 times (resistive), 100000 times (inductive)

CPU core specifications

Project parameters

71 types of instructions (12 basic+59 special)

Execution speed basic instruction 3-18 μ s

Maximum memory of 24K words

512 I/O points

Timer/counter 128 points

Isolation withstand voltage 1500VAC for 1 minute

Key issues

Question 1: What are the limitations of the C500 PLC’s expansion architecture? What are the maximum I/O points and expansion rules?

Answer: Adopting a CPU rack+extended I/O rack structure; Up to 3 expansion racks can be expanded, with a maximum length of 2m for a single expansion cable and a total length of ≤ 12m. The system supports a maximum of 512 I/O points; The CPU rack needs to be equipped with an I/O control unit, and each expansion rack must be equipped with an I/O interface unit.

Question 2: What are the mandatory safety requirements for wiring and grounding of C500 PLC? What are the consequences of non-compliance?

Answer: Cold pressed terminals must be used, and the terminal torque must meet the standard; The distance between the strong current and the I/O line is ≥ 300mm; the grounding resistance is * * ≤ 100 Ω * *, the wire diameter is ≥ 2mm ², and it is independently grounded. Failure to comply may result in interference, system crashes, erroneous outputs, electrical leakage, and module breakdown.

Question 3: What are the battery and fuse specifications for C500? What are the key time requirements for replacement?

Answer: The battery has a lifespan of 4 years and must be replaced within 1 week after an alarm. Replacement should be completed within 5 minutes to prevent program loss; Fuse specification 3A/250V (MF61NR), replacement must be completely powered off.