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 الاتصال التحول (1ج/س) إصدار; RM17TG20 in the same series is the 2C/O dual-contact model
✅ Core Functions
Monitors three phases L1/L2/L3:
- خطأ في تسلسل المرحلة (reverse phase, motor reverse rotation protection)
- Phase loss fault (loss of two or more phases; single-phase weak voltage drop will NOT trigger)
تعمل بالطاقة الذاتية, energized directly from L1/L2/L3, no additional auxiliary مزود الطاقة مطلوب
📋 Key Technical Specifications
| غرض | المعلمة |
| Monitoring Voltage Range | 208~480 VAC (operating limit 183~528VAC) |
| تكرار | 50/60Hz ±10% |
| اتصالات الإخراج | 1ج/س (1 مفتوح عادة + 1 مغلق عادة) |
| تصنيف الاتصال الحالي | 5A @250VAC, max.1250VA |
| Power-up Start Delay | ≤650ms |
| Fault Response Time | ≤130ms |
| استهلاك الطاقة | ≤22VA @400VAC 50Hz |
| تصاعد | 35مم DIN السكك الحديدية, width 17.5mm (1 وحدة) |
| مؤشر | Yellow LED: ON under normal condition, OFF in fault state |
| الشهادات | م, الجهد الزائد الفئة الثالثة, IEC60255 |
🔌 Terminal Wiring Definition
المحطات العليا: L1, L2, L3 → Connect to three-phase power supply
Lower contact terminals:
11: شائع
14: مفتوح عادة (لا) (closed in normal state, open under fault)
12: مغلق عادة (نورث كارولاينا) (مفتوحة في الحالة الطبيعية, closed under fault)
With correct three-phase supply and proper phase sequence: relay energizes, LED ON; خسارة المرحلة / reversed phase → relay de-energizes, LED OFF
🛠️ Typical Application Scenarios
Hoisting equipment, مصاعد, conveyor lines, water pump sets, preventing motor reverse rotation
ضواغط الهواء, chiller unit three-phase power protection
Portable equipment power access detection, emergency power switching judgment
⚠️ Troubleshooting Points
- إيقاف تشغيل الصمام: No power on three-phase incoming lines or loose wiring;
- LED fails to energize after power-up: Most likely reversed phase sequence, swap any two L phases;
- Single-phase voltage drop will not trigger RM17TG00. TG series only detects complete phase loss and does not monitor voltage unbalance. For unbalance/overvoltage & حماية الجهد المنخفض, select RM17TE series.
🧩 Same-series Comparison & مرجع الاستبدال
RM17TG00: 1ج/س, تسلسل المرحلة + خسارة المرحلة
RM17TG20: 2C/O dual changeover contacts, تسلسل المرحلة + خسارة المرحلة
RM17TE00: With voltage unbalance, الجهد الزائد, انخفاض الجهد, 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.
شنايدر RM17TG20 Troubleshooting Document
ملائم: RM17TG00 / RM17TG20 three-phase phase sequence & phase loss relay
Safety Precaution: 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. الحالة الطبيعية: yellow LED ON, both contact sets energized; Fault state: yellow LED OFF, both contact sets de-energized
- Pre-check Preparation
- أدوات: المتر الرقمي, cross screwdriver, القفازات العازلة
- تأكيد النموذج: RM17TG20, rated monitoring voltage 208~440VAC (limit 183~484VAC), long-term operation above 440VAC is not permitted
- System Confirmation: Three-phase 3-wire system, no neutral wire connected; this model cannot detect single-phase drop in 3P4W system
- Basic Status Description: ≤650ms initialization delay after power on; fault response ≤130ms; relay stays de-energized when fault exists, auto-recovers once fault cleared
- Troubleshooting by Fault Symptom
أعراض 1: Yellow LED completely off after power-up, relay contacts no action
وصف: No indicator light after energizing, اتصالات 11/14 و 21/24 fail to close
- خارج السلطة, inspect L1/L2/L3 terminals: Check for looseness, oxidation or poor crimping; clean dust and copper oxide on terminals
- تشغيل الطاقة, 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
- 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: Cracked housing, 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
أعراض 2: Three-phase supply normal, LED stays off, relay continuously reports fault (contacts not energized)
Most frequent on-site fault: Reversed phase sequence
- Measure three line voltages and confirm all values between 183~484VAC with balanced three-phase voltage
- خارج السلطة, swap any two incoming L phases (على سبيل المثال. L1 و L3)
- 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
- 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
- Still invalid: Relay internal failure, replace for test
أعراض 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 و 21/22/24, both act synchronously
- Power off and verify contact wiring:
11, 21: Common terminals
14, 24: مفتوح عادة (لا) (closed when energized; open under fault)
12, 22: مغلق عادة (نورث كارولاينا) (open when energized; closed under fault)
- تشغيل الطاقة (relay normal state, LED ON), measure continuity with multimeter:
11 & 14, 21 & 24: should conduct; 11 & 12, 21 & 22: should be open
- Manually create fault (reverse phase sequence), LED OFF:
11 & 14, 21 & 24: يفتح; 11 & 12, 21 & 22: conduct
- Asynchronous action between two contact sets (one closed, one open): Internal contact damage, must replace relay
- Contact status correct but no signal on downstream circuit: Check PLC DI module, external interlock circuit, broken secondary wiring or blown fuse
أعراض 4: Random false tripping during motor operation (LED OFF, protection trip)
- 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
- Inspect main circuit contactor, thermal relay terminals and cable lugs for loose connections, overheating and poor contact under high current
- Check power cables: Cable damage, earth fault or risk of phase-to-phase short circuit
- EMI Troubleshooting: Relay routed in parallel with power cables; relocate RM17TG away from VFDs and contactors, use separate cable trunking or shielding
- Confirm supply voltage does not exceed RM17TG20 upper limit 440VAC; use RM17TG00 for 480VAC application
- Cross replacement test: If fault disappears after installing new relay, original relay is aged and damaged
أعراض 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, الجهد الزائد & undervoltage protection required: Replace with RM17TE00 multi-function monitoring relay
ثالثا. Quick Self-check Procedure (On-site Maintenance Checklist)
✅ Step1: خارج السلطة, inspect appearance and wiring (محطات, burn marks, رخاوة)
✅ Step2: Power on and measure L1-L2 / L2-L3 / L1-L3 line-to-line voltages
✅ Step3: Observe LED status to locate fault domain (مزود الطاقة / تسلسل المرحلة / 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
- المفاهيم الخاطئة الشائعة
- ❌مفهوم خاطئ: Relay should protect on single-phase loss
✅ Note: TG series only detects loss of two or more phases; single-phase breakage is not detected.
- ❌مفهوم خاطئ: Front panel adjustment knobs are available for threshold setting
✅ Note: RM17TG has no potentiometer, threshold fixed.
- ❌مفهوم خاطئ: Two contact sets can act independently
✅ Note: Two contact sets operate synchronously; asynchronous action indicates relay damage.
- ❌مفهوم خاطئ: Can be used in 3P4W system (with neutral wire)
✅ Note: For three-phase 3-wire only, neutral wire must NOT be connected.
- Replacement Criteria (Replace relay if any condition met)
- L1/L2/L3 supply voltage normal, LED remains OFF after phase sequence swap
- Two contact sets act asynchronously, contacts burnt or fail to switch
- Housing or terminals show black burn marks, bulging or carbonization
- Fault eliminated after installing new relay under same power condition
- Maintenance Recommendation
- Periodic inspection: Tighten L1/L2/L3 input terminals and contact terminals quarterly to prevent vibration-induced looseness
- Ambient condition: Operating temperature -20~+60℃; avoid heavy dust, humid or corrosive gas environment
- تنظيف: Clean module surface dust with dry brush after power cut, liquid cleaner prohibited
- خدمة الحياة: Mechanical life of contacts >10 مليون دورة; electrical life approx.100,000 cycles at 5A@250VAC
Schneider RM17 Series Three-phase Monitoring Relay Full List (Harmony Zelio, 35مم DIN السكك الحديدية, 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
- RM17TG (النموذج الأساسي: تسلسل المرحلة + phase loss only, no adjustment knobs, fixed threshold)
| نموذج | اتصالات | نطاق الجهد | الوظائف الأساسية | تطبيق نموذجي |
| RM17TG00 | 1ج/س (1 changeover) | 208~480VAC | خطأ في تسلسل المرحلة, ≥2 phases loss protection; No unbalance / زيادة&انخفاض الجهد | Single interlock, water pump and general motor protection |
| RM17TG20 | 2ج/س (2 independent changeover) | 208~440VAC | خطأ في تسلسل المرحلة, ≥2 phases loss protection; No unbalance / زيادة&انخفاض الجهد | Hardware interlock + PLC alarm, hoisting, elevator |
TG Series Features: No potentiometer, no adjustment window on housing, only yellow status LED; Single-phase voltage drop will not trigger alarm
- RM17TT / مواجهة / TU / TE (Multi-function adjustable type, transparent cover with adjustment knobs)
| نموذج | اتصالات | نطاق الجهد | وظائف المراقبة | |
| RM17TT00 | 1ج/س | 208~480VAC | خسارة المرحلة + تسلسل المرحلة; rated voltage selectable, delay adjustable; No voltage unbalance, أكثر من / انخفاض الجهد | Basic adjustable phase sequence & خسارة المرحلة, suitable for multi-voltage site |
| RM17TA00 | 1ج/س | 208~480VAC | خسارة المرحلة + تسلسل المرحلة + three-phase voltage unbalance; unbalance threshold & delay adjustable; No over/undervoltage | Motor winding protection, detect three-phase asymmetry |
| RM17TU00 | 1ج/س | 208~480VAC | خسارة المرحلة + تسلسل المرحلة + undervoltage monitoring; undervoltage threshold & delay adjustable; No overvoltage, no unbalance | Power supply drop monitoring, generator set, incoming power supervision |
| RM17TE00 | 1ج/س | 208~480VAC | وظائف كاملة: phase loss+phase sequence+voltage unbalance+overvoltage+undervoltage, multiple potentiometers adjustable, true RMS measurement | مبرد, ضاغط الهواء, UPS switching, full protection requirement |
ثالثا. RM17 Series Single-phase / DC Voltage Monitoring (نفس السلسلة, non three-phase)
| نموذج | يكتب | Monitoring Range | اتصالات |
| RM17UAS14 | الجهد المستمر | 9~15VDC | 1ج/س |
| RM17UAS16 | التيار المتناوب/تيار مستمر عالمي | 20~80V AC/DC | 1ج/س |
| RM17UAS15 | التيار المتناوب/تيار مستمر عالمي | 65~260V AC/DC | 1ج/س |
| RM17UBE Series | Single-phase AC Over & انخفاض الجهد | 24~240VAC | 1ج/س |
| RM17UB310 | Single-phase Voltage Monitoring | 200~240VAC | 1ج/س |
- Model Suffix Coding Definition (RM17Txx00)
TG: النوع الأساسي, fixed threshold, no adjustment knob, تسلسل المرحلة + خسارة المرحلة
تي تي: Adjustable basic model, تسلسل المرحلة + خسارة المرحلة, voltage range selectable
مواجهة: ت + Asymmetry voltage unbalance detection
TU: ت + Undervoltage monitoring
TE: Total full functions (تسلسل المرحلة, خسارة المرحلة, unbalance, الجهد الزائد, انخفاض الجهد)
00: 1C/O output
20: 2C/O dual independent changeover contacts (only available for TG series)
- جدول الاختيار السريع (Three-phase models)
| متطلبات | النموذج الموصى به |
| Only phase sequence+phase loss, single contact output, 480V application | RM17TG00 |
| Phase sequence+phase loss, dual independent dry contacts for interlock + إنذار | RM17TG20 |
| Phase loss+phase sequence, multi-voltage option, delay required | RM17TT00 |
| Phase loss+phase sequence+three-phase unbalance (motor asymmetry protection) | RM17TA00 |
| Phase loss+phase sequence+undervoltage monitoring | RM17TU00 |
| الحماية الكاملة: phase loss+phase sequence+unbalance+overvoltage+undervoltage | RM17TE00 |
- Common General Specifications
- تصاعد: 35مم DIN السكك الحديدية, 1 وحدة (17.5مم);
- Output Logic: Relay energized (power normal) → contacts closed; fault → contacts open (fail-safe type);
- مزود الطاقة: Self-powered directly from L1/L2/L3, no neutral wire, three-phase 3-wire system only;
- وقت الاستجابة: TG fixed ≤130ms; TT/TA/TU/TE fault delay manually adjustable;
- تقييم الاتصال: 5A 250VAC resistive load; for PLC DI and contactor interlock circuit, not for direct driving of high-power loads
سابعا. استبدال & Upgrade Reference
RM17TG00 ↔ RM17TG20: identical function, only contact quantity differs
RM17TT00 → RM17TA00: add voltage unbalance detection
RM17TA00 → RM17TE00: add overvoltage and undervoltage window monitoring
Legacy RM22TG series is substitute series (نفس الوظيفة, different form factor)
المقاولين,قاطع الدائرة,الاستشعار,التشفير,بلك,محول




















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