Schneider RM17TG00 Phase Sequence & รีเลย์ตรวจสอบการสูญเสียเฟส

RM17: Harmony RM17 series three-phase monitoring relay

TG: Monitors phase sequence and phase loss only (no voltage unbalance, overvoltage or undervoltage functions)

00: 1 การติดต่อเปลี่ยนแปลง (1ซี/โอ) รุ่น; RM17TG20 in the same series is the 2C/O dual-contact model

✅ ฟังก์ชั่นหลัก

Monitors three phases L1/L2/L3:

1. ข้อผิดพลาดลำดับเฟส (reverse phase, motor reverse rotation protection)
2. Phase loss fault (loss of two or more phases; single-phase weak voltage drop will NOT trigger)

Self-powered, energized directly from L1/L2/L3, no additional auxiliary แหล่งจ่ายไฟ ที่จำเป็น

📋 Key Technical Specifications

🔌 Terminal Wiring Definition

อาคารผู้โดยสารด้านบน: L1, L2, L3 → Connect to three-phase power supply

Lower contact terminals:

11: ทั่วไป

14: เปิดตามปกติ (เลขที่) (closed in normal state, เปิดภายใต้ความผิด)

12: ปกติปิด (เอ็นซี) (เปิดในสภาวะปกติ, closed under fault)

With correct three-phase supply and proper phase sequence: รีเลย์รวมพลัง, LED ON; การสูญเสียเฟส / reversed phase → relay de-energizes, LED OFF

🛠️ สถานการณ์การใช้งานทั่วไป

Hoisting equipment, ลิฟต์, สายลำเลียง, water pump sets, preventing motor reverse rotation

เครื่องอัดอากาศ, chiller unit three-phase power protection

Portable equipment power access detection, emergency power switching judgment

⚠️ Troubleshooting Points

1. ไฟแอลอีดีดับลง: No power on three-phase incoming lines or loose wiring;
2. LED fails to energize after power-up: Most likely reversed phase sequence, swap any two L phases;
3. Single-phase voltage drop will not trigger RM17TG00. TG series only detects complete phase loss and does not monitor voltage unbalance. For unbalance/overvoltage & การป้องกันแรงดันตก, select RM17TE series.

🧩 Same-series Comparison & การอ้างอิงทดแทน

RM17TG00: 1ซี/โอ, ลำดับเฟส + การสูญเสียเฟส

RM17TG20: 2C/O dual changeover contacts, ลำดับเฟส + การสูญเสียเฟส

RM17TE00: With voltage unbalance, แรงดันไฟฟ้าเกิน, แรงดันตก, phase loss and phase sequence (full-featured model)

📌 Notes

No potentiometer for threshold adjustment, fixed logic without adjustment knobs;

For three-phase 3-wire system only;

Dry contact output for PLC DI or contactor coil interlock circuit.

ชไนเดอร์ RM17TG20 Troubleshooting Document

ใช้งานได้: RM17TG00 / RM17TG20 three-phase phase sequence & phase loss relay

ข้อควรระวังด้านความปลอดภัย: High-voltage work must follow power cut & voltage verification. Use qualified high-voltage multimeter and wear insulated protective gear for three-phase voltage measurement.

Product Principle Review: Only monitors phase sequence and complete loss of two or more phases; single-phase voltage drop and voltage unbalance will not trigger protection. Self-powered from L1/L2/L3. สภาวะปกติ: yellow LED ON, both contact sets energized; Fault state: yellow LED OFF, both contact sets de-energized

1. Pre-check Preparation
2. เครื่องมือ: มัลติมิเตอร์แบบดิจิตอล, cross screwdriver, ถุงมือฉนวน
3. การยืนยันรุ่น: RM17TG20, rated monitoring voltage 208~440VAC (limit 183~484VAC), long-term operation above 440VAC is not permitted
4. System Confirmation: Three-phase 3-wire system, no neutral wire connected; this model cannot detect single-phase drop in 3P4W system
5. Basic Status Description: ≤650ms initialization delay after power on; fault response ≤130ms; relay stays de-energized when fault exists, auto-recovers once fault cleared
6. Troubleshooting by Fault Symptom

อาการ 1: Yellow LED completely off after power-up, relay contacts no action

คำอธิบาย: No indicator light after energizing, ผู้ติดต่อ 11/14 และ 21/24 fail to close

1. ปิดเครื่อง, inspect L1/L2/L3 terminals: Check for looseness, oxidation or poor crimping; clean dust and copper oxide on terminals
2. เปิดเครื่อง, measure line-to-line voltage L1-L2, L2-L3, L1-L3 at relay upper terminals with multimeter

Any line voltage ＜183V: Undervoltage on power supply, relay cannot operate; check upstream circuit breaker, fuse and cable breakage

No voltage on two or more phases: Upstream phase loss fault, repair power supply circuit

3. LED still OFF with all three-phase voltages normal:

Check miswiring of L1/L2/L3; confirm power cables are not connected to contact terminals

Inspect module appearance: ที่อยู่อาศัยแตกร้าว, burn marks or carbonized terminals → internal damage, replace relay directly

Cross test: Remove relay and connect to known good three-phase supply; if LED remains off, relay is defective

อาการ 2: Three-phase supply normal, LED stays off, relay continuously reports fault (contacts not energized)

Most frequent on-site fault: ลำดับเฟสย้อนกลับ

1. Measure three line voltages and confirm all values between 183~484VAC with balanced three-phase voltage
2. ปิดเครื่อง, swap any two incoming L phases (เช่น. L1 และ L3)
3. Re-energize and observe LED:

LED ON and contacts close: Fault resolved, root cause reversed phase sequence

LED still OFF after twice phase swap: proceed to next step

4. Check for virtual connection with induced voltage: Multimeter shows normal voltage but voltage collapses under load. TG series cannot identify weak single-phase drop, but will trigger phase loss alarm if single-phase voltage falls below 100V
5. Still invalid: Relay internal failure, replace for test

อาการ 3: LED is ON, but no signal on output contact circuit (no PLC feedback / contactor fails to act)

Power monitoring circuit healthy, fault lies in secondary dry contact circuit

RM17TG20 has two independent changeover contact sets: 11/12/14 และ 21/22/24, both act synchronously

1. Power off and verify contact wiring:

11, 21: ขั้วทั่วไป

14, 24: เปิดตามปกติ (เลขที่) (closed when energized; เปิดภายใต้ความผิด)

12, 22: ปกติปิด (เอ็นซี) (open when energized; closed under fault)

2. เปิดเครื่อง (relay normal state, LED ON), measure continuity with multimeter:

11 & 14, 21 & 24: should conduct; 11 & 12, 21 & 22: should be open

3. Manually create fault (reverse phase sequence), LED OFF:

11 & 14, 21 & 24: เปิด; 11 & 12, 21 & 22: จัดการ

4. Asynchronous action between two contact sets (one closed, one open): Internal contact damage, must replace relay
5. Contact status correct but no signal on downstream circuit: Check PLC DI module, external interlock circuit, broken secondary wiring or blown fuse

อาการ 4: Random false tripping during motor operation (LED OFF, protection trip)

1. Monitor three-phase voltage, focus on voltage dip during motor starting:

⚠️ Important Limitation: RM17TG only detects complete loss of two phases; single-phase voltage dip will not trigger protection. Random tripping is mostly caused by instantaneous two-phase power loss or poor connection

2. Inspect main circuit contactor, thermal relay terminals and cable lugs for loose connections, overheating and poor contact under high current
3. Check power cables: สายเคเบิลเสียหาย, earth fault or risk of phase-to-phase short circuit
4. EMI Troubleshooting: Relay routed in parallel with power cables; relocate RM17TG away from VFDs and contactors, use separate cable trunking or shielding
5. Confirm supply voltage does not exceed RM17TG20 upper limit 440VAC; use RM17TG00 for 480VAC application
6. Cross replacement test: If fault disappears after installing new relay, original relay is aged and damaged

อาการ 5: Relay does not alarm with single-phase cut-off (protection no action)

This is NOT a fault, it is inherent design limitation!

RM17TG series only detects loss of ≥2 phases. Single-phase disconnection and single-phase voltage drop cannot trigger protection

If single-phase loss, voltage unbalance, แรงดันไฟฟ้าเกิน & undervoltage protection required: Replace with RM17TE00 multi-function monitoring relay

III. Quick Self-check Procedure (On-site Maintenance Checklist)

✅ Step1: ปิดเครื่อง, inspect appearance and wiring (ขั้ว, burn marks, looseness)

✅ Step2: Power on and measure L1-L2 / L2-L3 / L1-L3 line-to-line voltages

✅ Step3: Observe LED status to locate fault domain (แหล่งจ่ายไฟ / ลำดับเฟส / relay itself)

✅ Step4: Power off and swap two L phases to verify reversed phase sequence

✅ Step5: Power off and test continuity of two contact sets to confirm switching logic

✅ Step6: Cross replace relay to confirm whether fault comes from relay or external wiring

1. ความเข้าใจผิดที่พบบ่อย
2. ❌ความเข้าใจผิด: Relay should protect on single-phase loss

✅ Note: TG series only detects loss of two or more phases; single-phase breakage is not detected.

2. ❌ความเข้าใจผิด: Front panel adjustment knobs are available for threshold setting

✅ Note: RM17TG has no potentiometer, threshold fixed.

3. ❌ความเข้าใจผิด: Two contact sets can act independently

✅ Note: Two contact sets operate synchronously; asynchronous action indicates relay damage.

4. ❌ความเข้าใจผิด: Can be used in 3P4W system (ด้วยลวดที่เป็นกลาง)

✅ Note: For three-phase 3-wire only, neutral wire must NOT be connected.

1. Replacement Criteria (Replace relay if any condition met)
2. L1/L2/L3 supply voltage normal, LED remains OFF after phase sequence swap
3. Two contact sets act asynchronously, contacts burnt or fail to switch
4. Housing or terminals show black burn marks, bulging or carbonization
5. Fault eliminated after installing new relay under same power condition
6. คำแนะนำการบำรุงรักษา
7. Periodic inspection: Tighten L1/L2/L3 input terminals and contact terminals quarterly to prevent vibration-induced looseness
8. Ambient condition: Operating temperature -20~+60℃; avoid heavy dust, humid or corrosive gas environment
9. การทำความสะอาด: Clean module surface dust with dry brush after power cut, liquid cleaner prohibited
10. อายุการใช้งาน: Mechanical life of contacts >10 ล้านรอบ; electrical life approx.100,000 cycles at 5A@250VAC

Schneider RM17 Series Three-phase Monitoring Relay Full List (Harmony Zelio, 35ราง DIN มม, 17.5mm 1-module width)

All models are self-powered from L1/L2/L3, no auxiliary supply required, 5A@250VAC dry contact output, for three-phase 3-wire system

1. RM17TG (โมเดลพื้นฐาน: ลำดับเฟส + phase loss only, no adjustment knobs, fixed threshold)

TG Series Features: No potentiometer, no adjustment window on housing, only yellow status LED; Single-phase voltage drop will not trigger alarm

1. RM17TT / เผชิญหน้า / TU / ที่ (Multi-function adjustable type, transparent cover with adjustment knobs)

III. RM17 Series Single-phase / DC Voltage Monitoring (ซีรีย์เดียวกัน, non three-phase)

1. Model Suffix Coding Definition (RM17Txx00)

TG: ประเภทพื้นฐาน, fixed threshold, no adjustment knob, ลำดับเฟส + การสูญเสียเฟส

ทีที: Adjustable basic model, ลำดับเฟส + การสูญเสียเฟส, voltage range selectable

เผชิญหน้า: ต + Asymmetry voltage unbalance detection

TU: ต + Undervoltage monitoring

ที่: Total full functions (ลำดับเฟส, การสูญเสียเฟส, ไม่สมดุล, แรงดันไฟฟ้าเกิน, แรงดันตก)

00: 1C/O output

20: 2C/O dual independent changeover contacts (only available for TG series)

1. ตารางการเลือกด่วน (Three-phase models)

1. Common General Specifications
2. การติดตั้ง: 35ราง DIN มม, 1 โมดูล (17.5มม);
3. Output Logic: Relay energized (power normal) → contacts closed; fault → contacts open (fail-safe type);
4. พาวเวอร์ซัพพลาย: Self-powered directly from L1/L2/L3, no neutral wire, three-phase 3-wire system only;
5. เวลาตอบสนอง: TG fixed ≤130ms; TT/TA/TU/TE fault delay manually adjustable;
6. เรตติ้งการติดต่อ: 5A 250VAC resistive load; for PLC DI and contactor interlock circuit, not for direct driving of high-power loads

ปกเกล้าเจ้าอยู่หัว. การทดแทน & Upgrade Reference

RM17TG00 ↔ RM17TG20: ฟังก์ชั่นที่เหมือนกัน, only contact quantity differs

RM17TT00 → RM17TA00: add voltage unbalance detection

RM17TA00 → RM17TE00: add overvoltage and undervoltage window monitoring

Legacy RM22TG series is substitute series (ฟังก์ชั่นเดียวกัน, different form factor)