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Phoenix Contact UM-IC14-8R/DO/1NO/DRY/S7: 8-channel dry contact relay module dedicated for S7-300 (Order No.: 2902889)
- Model Code Explanation
| Code Segment | Description |
| UM | Product series code, VARIOFACE interface module series (Universal Module) |
| IC14 | Interface type, 14-pin IDC/FLK header, compatible with Siemens S7-300/ET200M |
| 8R | 8-channel Relay Output |
| DO | Digital Output |
| 1NO | Contact configuration: 1 Normally Open contact |
| DRY | Contact type: Dry contact (no built-in power supply) |
| S7 | Compatible controller: Siemens S7 series PLC |
| 2902889 | Official Phoenix Contact order number |
- Main Specifications
| Item | Specifications | Remarks |
| General Features | ||
| Product Type | 8-channel digital output relay module | Front-mounted for S7-300/ET200M I/O cards |
| Contact Configuration | 1 dry normally open contact per channel | No internal power supply; external voltage required for loads |
| Rated Load Current | 3 A per channel (resistive load) | Max. switching voltage: 250 V AC / 30 V DC |
| Mechanical Lifespan | 2×10⁷ switching cycles | Electrical lifespan: 10⁵ cycles at rated load |
| Input Voltage | 24 V DC ±10% | Operating range: 21.6 – 26.4 V DC |
| Electrical Characteristics | ||
| Input Current | 9.5 mA per channel @ 24 V DC | Equipped with freewheeling diode for protection |
| Dielectric Strength | 4 kV (basic insulation) | Overvoltage Category III, Pollution Degree 2 |
| Isolation Type | Optocoupler isolation between channels, coils and contacts | Compliant with IEC 60664 |
| Connection Features | ||
| Controller Side | 14-pin IDC/FLK header (2.54 mm pin pitch) | Matches S7-300 digital output cards e.g. 6ES7322-1BL00 |
| Field Side | Screw connection | Solid wire: 0.2 – 4 mm²; Stranded wire: 0.2 – 2.5 mm² |
| Physical Characteristics | ||
| Dimensions (W×H×D) | 90 × 65 × 92 mm | Mounted on standard NS 35/7.5 DIN rail |
| Weight | Approx. 142 g | Packing unit: 1 piece per box |
| Operating Temperature | -20 °C to +50 °C | Storage temperature: -40 °C to +85 °C |
| Status Indication | Green LED (Power), Yellow LED (Channel output) | Clear operating status display |
- Full Model List (UM-IC14 Series S7-specific Relay Modules)
| Order No. | Model | Contact Configuration | Contact Type | Rated Current | Application Scenarios |
| 2902889 | UM-IC14/8R/DO/1NO/DRY/S7 | 1NO per channel | Dry contact | 3 A | General digital output for externally powered loads |
| 2902891 | UM-IC14/8R/DO/1CO/DRY/S7 | 1 Changeover contact per channel | Dry contact | 10 A | High-current loads with common terminal switching |
| 2902892 | UM-IC14/8R/DO/1CO/WET/S7 | 1 Changeover contact per channel | Wet contact | 4 A | Direct drive for 24 V DC / 230 V AC loads |
| 2902893 | UM-IC14/8R/DO/1NO/WET/S7 | 1NO per channel | Wet contact | 4 A | Direct drive for 24 V DC loads, no external power needed |
| 2902896 | UM-IC14/8DO/F/LA/S7 | Straight-through (no relay) | Transistor output | 0.8 A | Low-current signal transmission with fuse protection |
- Replacement Models & Competitor Comparison
4.1 Official Phoenix Contact Replacements
| Original Model | Recommended Replacement | Compatibility | Improvements |
| 2902889 | UMK-8RM/MR-G24/1/PLC (2979469) | Requires adaptation for S7-1500 | Pluggable relays for easier maintenance |
| 2902889 | UM-IC14/8R/DO/1CO/DRY/S7 (2902891) | Fully compatible | Changeover contacts for more control applications |
| 2902889 | REL-MR-G24/1 (2966024) + Base | Rewiring required | Independent relays for lower cost |
4.2 Cross-brand Competitor Comparison (Function Compatibility)
| Brand | Model | Contact Configuration | Rated Current | Compatible PLC | Price Range |
| Weidmüller | DRM 570024 | 1NO per channel | 3 A | S7-300 | Medium |
| Schneider Electric | Zelio RSH21 | 1NO per channel | 3 A | General use | Medium |
| Siemens | 3RH2911-1HA11 | 1NO per channel | 3 A | S7-300 | Medium-High |
| Phoenix Contact | 2902889 | 1NO per channel | 3 A | S7-300 | Medium |
| Chint | NXR-25 | 1NO per channel | 5 A | General use | Low |
- Application Environment & Industry Cases
5.1 Applicable Scenarios (Advantage Matching)
✅ Siemens S7-300/ET200M System Expansion: Front installation without cabinet modification for quick addition of digital output points
✅ Industrial Automation Production Lines: Control solenoid valves, contactors, indicators and other actuators to realize process automation
✅ Process Control Systems: Isolate PLC outputs from field high-voltage signals in chemical and power industries to enhance system safety
✅ Building Automation: HVAC and lighting system control; dry contacts adapt to various load types
✅ Equipment Manufacturing: Standard interface for OEM machines such as packaging machines, printers and CNC machine tools to shorten development cycle
5.2 Not Recommended Scenarios (Limitations)
❌ High-frequency Switching Applications: Limited mechanical contact lifespan; not suitable for switching over 10 times per second (Solid State Relays are recommended)
❌ High-current Loads: 3 A maximum per channel; do not drive high-power equipment like motors directly (use contactors for transition)
❌ Explosion-proof Areas: No explosion-proof certification; use dedicated explosion-proof modules or install inside certified explosion-proof cabinets
❌ S7-1200/1500 Systems: Incompatible interface; select corresponding UMK series modules e.g. UMK-8RM/MR-G24/1/PLC
5.3 Typical Application Cases
Case 1: S7-300 Control System for Automotive Component Assembly Lines
Configuration: S7-300 CPU 315-2DP + 6ES7322-1BL00-0AA0 DO card + 4 pcs of 2902889 modules
Functions: Control 16 pneumatic actuators and 16 indicator lights for sequential processes including bolt tightening and component pressing
Advantages: Dry contacts support mixed loads of different voltages (24 V DC solenoid valves, 220 V AC indicators); optocoupler isolation protects PLC cards against field interference
Key Technology: Seamless connection with S7-300 DO cards via FLK cables to reduce wiring errors
Case 2: Status Indication System for Food & Beverage Filling Lines
Configuration: ET200M distributed I/O station + 2902889 module + 8 pcs of 24 V DC indicators
Functions: Real-time status display for 8 working procedures including bottle washing, filling, capping and labeling; automatic alarm upon faults
Advantages: LED indicators enable quick fault location; dry contacts eliminate power conflicts and improve system stability
Maintenance: Modules can be removed and replaced without power cut to minimize downtime
- Troubleshooting & Maintenance Guide
6.1 LED Indicator Diagnosis
| Indicator | Color | Status | Meaning | Recommendations |
| Power | Green | Off | No 24 V DC input | Check output voltage of DO card and wiring |
| Power | Green | On | Normal power supply | Operating normally |
| Channel | Yellow | Off | No output signal | Check PLC program output and module address settings |
| Channel | Yellow | On | Normal output signal | Inspect field load wiring and test contact continuity |
| Channel | Yellow | Flashing | Output short circuit / overload | Disconnect loads, troubleshoot short circuits and replace faulty channels |
6.2 Common Faults & Solutions
| Fault Phenomenon | Possible Causes | Solutions |
| No module output | 1. Power failure or abnormal voltage | 1. Measure terminal voltage (21.6–26.4 V DC) |
| 2. No output from PLC program | 2. Monitor DO status via programming software | |
| 3. Incorrect module address | 3. Verify I/O address allocation and re-download hardware configuration | |
| 4. Poor header connection | 4. Reconnect FLK cable and check for bent pins | |
| Poor contact performance | 1. Oxidized contacts | 1. Clean contacts or replace the module |
| 2. Load current exceeds 3 A rating | 2. Reduce load or add intermediate contactors | |
| 3. Loose wiring caused by vibration | 3. Retighten field terminal connections | |
| LED on but no output | 1. Burned contacts | 1. Measure contact resistance to check continuity |
| 2. Open-circuited load | 2. Inspect and replace defective loads | |
| 3. Wrong common terminal wiring | 3. Recheck common terminal wiring to match load power | |
| Severe overheating | 1. Ambient temperature over 50 °C | 1. Improve ventilation and lower ambient temperature |
| 2. Full-load operation of multiple channels | 2. Distribute loads and avoid full load on all channels simultaneously | |
| 3. Poor heat dissipation | 3. Reserve at least 5 mm clearance around the module for heat dissipation |
6.3 Maintenance Schedule & Notes
| Maintenance Item | Cycle | Operation Notes |
| Module Cleaning | Every 3 months | Cut off power first; remove dust with dry compressed air. Do not use liquid cleaners. |
| Connection Inspection | Every 6 months | Check FLK headers and screw terminals for looseness and pin oxidation |
| Function Test | Every 1 month | Manually trigger each channel output and verify LED and contact operation |
| Load Current Check | Every 3 months | Measure current of each channel to ensure it does not exceed 3 A rating |
| Spare Parts Preparation | For critical systems | Prepare 1–2 spare modules for rapid replacement of faulty units |
- Selection Guidelines & Quick Reference Rules
7.1 Three Key Points for UM-IC14 Selection
- Contact Type: DRY dry contacts for multi-voltage loads; WET wet contacts for direct 24 V DC load drive
- Contact Configuration: 1NO for simple control; 1CO changeover contacts for common terminal switching
- Current Requirement: 3 A (1NO) for light loads; 10 A (1CO) for high-current loads
7.2 Troubleshooting Tips
LED off → Check power; LED on with no output → Check contacts; LED flashing → Check overload
Poor contact → Check load; Overheating → Check heat dissipation; Multi-channel failure → Check common terminal
7.3 Priority of Replacement Solutions
- Same series upgrade: 2902889 → 2902891 (1CO dry contact, 10 A)
- Easy maintenance: 2902889 → UMK-8RM/MR-G24/1/PLC (pluggable relays)
- System upgrade: 2902889 → UMK series modules compatible with S7-1500
Practical Application Cases of UM-IC14-8R/DO/1NO/DRY/S7 (2902889)
The following are widely applied field cases covering automotive, food, water treatment, HVAC and packaging machinery. All cases take advantage of its core features: compatibility with S7-300/ET200M, dry contact isolation and support for multi-voltage loads.
Case 1: Welding Production Line for Automotive Components (S7-300 Main Control)
System Configuration
PLC: S7-300 CPU 315-2DP
DO Card: 6ES7322-1BL00 (32-point DO)
Interface Module: 4 pcs of UM-IC14-8R/DO/1NO/DRY/S7 (32 relay outputs in total)
Loads: 24 V DC pneumatic solenoid valves, 220 V AC welding indicators, buzzers
Functions
Control clamping/releasing of welding fixtures, forward/retract of welding torches and interlock between working stations
Three-color indicators (Run/Standby/Fault) for each station
Dry contacts directly switch mixed 24 V DC and 220 V AC loads without cabinet modification or additional relays
Optocoupler isolation between PLC and field high voltage prevents malfunction caused by high-frequency interference from welding equipment
Benefits
Direct connection to DO card via prefabricated FLK14 cable reduces wiring time by 70%
Short circuit on field side only damages module channels without affecting PLC cards
Hot-swap replacement of individual modules during operation minimizes production downtime
Case 2: Food & Beverage Filling Line (ET200M Distributed I/O)
System Configuration
Remote I/O: ET200M IM153-1 + 6ES7322-1BH01 (16-point DO)
Interface Module: 2 pcs of UM-IC14-8R/DO/1NO/DRY/S7
Loads: 24 V DC proximity switch indicators, 220 V AC conveyor motor contactor coils, solenoid valves
Functions
Sequential linkage and interlock for bottle washing, filling, capping, labeling and inspection processes
Independent dry contacts per channel for actuators of different voltages
Yellow LEDs display real-time output status for quick on-site inspection
Built-in freewheeling protection extends service life of solenoid valve coils
Benefits
Distributed I/O stations realize relay output directly, eliminating intermediate relay cabinets
Wide temperature range (-20 °C ~ +50 °C) and IP20 rating ensure stable operation in humid and dusty food workshops
Non-polar dry contacts reduce on-site wiring errors
Case 3: Municipal Wastewater Treatment Plant (S7-300 for Rake, Pump & Valve Control)
System Configuration
PLC: S7-300 CPU 314C-2DP
DO Card: 6ES7322-1BL00
Interface Module: 3 pcs of UM-IC14-8R/DO/1NO/DRY/S7
Loads: 220 V AC mechanical rakes, lift pumps, electric valve control circuits
Functions
Timed start/stop of coarse and fine rakes and linkage control based on liquid level
Alternate operation and automatic switchover between primary and standby sewage pumps upon faults
Open/close and position indication for electric valves
Dry contacts directly drive 220 V AC contactor coils (≤3 A) without intermediate relays
Benefits
Compact cabinet layout saves space, materials and labor costs
Mechanical lifespan of 2×10⁷ cycles ensures reliable performance for frequently started pumps and valves
Independent common terminals facilitate grouped maintenance and power cut operations
Case 4: HVAC System of Large Commercial Buildings (Air Conditioning, Fresh Air & Smoke Exhaust)
System Configuration
PLC: S7-300 CPU 313C
DO Card: 6ES7322-1BH00
Interface Module: 2 pcs of UM-IC14-8R/DO/1NO/DRY/S7
Loads: 24 V DC air damper actuators, 220 V AC fan/air conditioning unit contactors, alarm buzzers
Functions
Proportional and on/off control for fresh air dampers, return air dampers and smoke exhaust dampers
Start/stop of air conditioning units and linkage with frequency converters
Fire linkage: Automatically close fresh air systems and activate smoke exhaust upon fire alarm
Dry contacts adapt to common 24 V / 220 V mixed control circuits in buildings
Benefits
Standard building control solution applicable to multiple floors and buildings
LED indicators help maintenance staff locate faulty circuits rapidly
Isolation design suppresses interference from inverters and dimming devices inside buildings
Case 5: Packaging Machinery (Vertical & Horizontal Packaging Machines)
System Configuration
PLC: S7-300 CPU 312
DO Card: 6ES7322-1BH01
Interface Module: 1 pc of UM-IC14-8R/DO/1NO/DRY/S7
Loads: 24 V DC cutting solenoid valves, feeding motor starters, material level alarm lights
Functions
Sequential control for packaging film feeding, positioning, cutting and sealing
High/low material level alarm and automatic stop for material shortage
Dry contacts directly drive low-power actuators to simplify electrical design of equipment
Benefits
Standardized design for OEM equipment ensures consistent wiring and fast commissioning in mass production
Compact size and DIN rail mounting suit narrow cabinets
Independent channels prevent faults on one channel from affecting overall machine operation
General Advantages Summary
Dedicated for S7-300/ET200M: Direct FLK14 connection, no adapters required and fewer wiring mistakes
Dry Contact (DRY): Compatible with 24 V, 220 V, 110 V and other common voltages for all types of low-power field loads
3 A per Channel: Ideal for solenoid valves, contactor coils, indicators and buzzers
Optocoupler Isolation: Protects PLC devices and provides strong anti-interference capability for harsh industrial environments
LED Status Indication: Greatly accelerates commissioning, inspection and maintenance work
