(位相シーケンス / 欠相 / 3-Phase Voltage Unbalance)
シリーズ: Zelio Control / Harmony RM17T Series, DIN rail mounted 3-phase monitoring relay, commonly known as phase sequence protector.
✅ Monitoring Functions
Phase sequence detection (L1-L2-L3): Instant trip upon reverse phase sequence
Phase loss detection: Instant trip if any phase is lost (including phase loss with regenerated voltage from motors)
3-phase voltage asymmetry (アンバランス): Adjustable threshold from 5% に 15% of Un, with time-delayed tripping
Logic rule: 位相反転 / phase loss → instantaneous trip; voltage unbalance → delayed trip.
📌 Key Electrical Specifications
Monitoring voltage range: AC 208~480V (operating limit: 183~528V AC)
頻度: 50/60 Hz (±10%)
Output contact: 1 C/O (SPDT), 5あ / 250VAC
Time delay adjustment: 0.1~10代 (only for unbalance faults)
Reset delay: 約. 1.5s
消費電力: ≤22VA @ 400V 50Hz
取り付け: DIN 35mm rail; width 17.5mm (1 モジュール幅)
表示: Status LED; sealed transparent cover prevents accidental parameter changes
🧮 RM17T Series Selection Comparison (Key for Model Selection)
RM17TT00: Phase sequence + 位相損失 (NO unbalance monitoring)
RM17TA00 (現行モデル): Phase sequence + 位相損失 + 3-phase voltage asymmetry
RM17TU00: Phase sequence + 位相損失 + 不足電圧
RM17TE00: Phase sequence + 位相損失 + asymmetry + 過電圧 + 不足電圧 (full-function model)
🛠️ Typical Application Scenarios
エレベーター, hoisting & conveying equipment, エアコンプレッサー, ウォーターポンプ, refrigeration units, 包装機械; prevents motor reverse rotation, burnout from phase loss, and overheating caused by three-phase unbalance.
🔌 Wiring Guidelines
- Connect L1/L2/L3 directly to the monitored three-phase supply (self-powered, no separate auxiliary supply required).
- 端子 15/16/18 form one changeover contact: 15-16 = normally closed; 15-18 = normally open.
- Panel setting: First select rated voltage (208/220/380/400/415/480V), then set unbalance threshold and fault delay time.
- Fault recovery: Automatic reset once power returns to normal; no manual reset button.
⚠️ Troubleshooting
Relay does not energize after power-up: Check phase sequence, 位相損失, and voltage range dip switch setting.
Frequent tripping during normal operation: Increase unbalance percentage threshold, extend time delay, and investigate single-phase load current imbalance.
No LED illumination: Three-phase input voltage exceeds the 183~528V operating range.
📎 Replacement Options
Direct upgraded replacement within the same product line: RM22TA33 (RM22 series, same functions with 2 C/O contacts).
国内代替品: チント / Delixi three-phase phase-sequence & unbalance monitoring relays.
- Full Model List of RM17T Series
(3-phase supply monitoring relays, 17.5mm single-module width, DINレール取付)
1) ベーシックモデル: RM17TG (Only phase sequence + 位相損失; no unbalance / undervoltage monitoring)
RM17TG00: 1 C/O changeover contact, 208~480V AC
RM17TG20: 2 C/O dual changeover contacts, 208~440V AC
2) Multifunction Models (RM17TT / フェイシング / TU / TE, 208~480V AC, 1 C/O contact uniformly)
| モデル | 主要な監視機能 |
| RM17TT00 | Phase sequence + 位相損失 (基本バージョン, no unbalance / 不足電圧) |
| RM17TA00 (現行モデル) | Phase sequence + 位相損失 + 3-phase voltage unbalance (asymmetry) |
| RM17TU00 | Phase sequence + 位相損失 + 不足電圧 |
| RM17TE00 | Phase sequence + 位相損失 + アンバランス + 過電圧 + 不足電圧 (full function) |
Abbreviation explanation:
TU = T + 不足電圧
TE = T + Everything (フル機能)
Ⅲ. Common Specifications for the Whole Series (All Models Identical)
電圧範囲: AC 208~480V (operating limit 183~528V)
接点定格: 5あ / 250VAC; RM17TG00/TT/TA/TU/TE = 1 C/O; only RM17TG20 = 2 C/O
幅: 17.5mm (1P module)
リセットモード: Automatic reset after fault clears; no manual reset button
- Upgraded Replacement Models (RM22 Series with Extra Contacts)
RM17TA00 → RM22TA33 (2 C/O contacts)
RM17TU00 → RM22TU23
RM17TE00 → RM22TE33
RM17TA00 Overall Dimensions (幅×高さ×奥行き)
17.5 mm× 90 mm× 72 mm
幅: 17.5 mm (1-pole module, same width as 1P MCB)
身長: 90 mm
深さ (from DIN rail front face): 72 mm
取り付け: DIN35 standard rail
正味重量: 約. 0.13 kg
✅ All models in RM17T series (RM17TT00 / RM17TU00 / RM17TE00 / RM17TG00) share identical dimensions.
Core Positioning of RM17TA00
It provides phase sequence + 位相損失 + three-phase voltage unbalance protection, mainly for three-phase asynchronous motors. It prevents reverse rotation, motor burnout from phase loss, and overheating caused by long-term voltage imbalance. セルフパワー, compact 1-module DIN rail design, ideal for compact control cabinets and retrofitting projects where no PLC signal collection is needed.
- 業界 & Equipment Applications
- 巻き上げ & 運ぶ (主な用途)
Overhead cranes, electric hoists, ベルトコンベア, stackers, エレベーター; prevents motor reverse rotation after phase reconnection and overheating damage to gearboxes and motors due to long-term unbalance.
- エレベーター & Lifting Platforms
Freight elevators, simple lifting platforms, parking lift power circuits; wrong phase sequence causes reverse car movement; voltage unbalance leads to excessive temperature rise of traction motors.
- ウォーターポンプ & Pumping Stations
High-power centrifugal pumps, submersible sewage pumps, pre-power monitoring before variable-frequency drives; unbalance is frequently caused by mixed single-phase loads in water supply, sewage treatment and chiller pump systems.
- エアコンプレッサー & HVAC Refrigeration Units
スクリューエアコンプレッサー, 冷水機, air-source heat pumps, 冷凍コンプレッサー; compressors are highly sensitive to three-phase unbalance, which easily burns out motor windings.
- 包装, 繊維 & Woodworking Automation
Packaging lines, 繊維機械, 押出機, injection molding auxiliary equipment; frequent power maintenance and phase swapping require phase sequence verification before power-on.
- ファン負荷
排気ファン, induced draft fans, drying fans; large inertia fans produce regenerated voltage after phase loss; this model supports phase loss detection under regenerated voltage conditions.
- Control Panels & OEM Equipment Matching
380V three-phase control cabinets, non-standard automation OEM factory-fitted protection; old equipment retrofits, hard-contact interlock without adding PLC analog modules.
- Selection Boundary: 適切な / 不適切なシナリオ
✅ おすすめ:
Three-phase motor loads with risks of voltage asymmetry overheating (core advantage over RM17TT00)
Supply voltage AC 208~480V, 50/60Hz
限られたキャビネットスペース, のみ 1 module width available
Hard-contact interlock directly wired into main contactor coil circuit
❌ 推奨されません:
過電圧 + undervoltage monitoring required → choose RM17TE00
Only undervoltage protection without unbalance → choose RM17TU00
Dual independent alarm contacts required → upgrade to RM22TA33 (2C/O)
Motors behind variable-frequency drives: VFDs already have built-in phase loss & アンバランス保護; extra relay is generally unnecessary.
Ⅲ. Typical Control Logic
Contact wired in series with the main contactor coil circuit:
Normal power supply → relay energizes and closes, contactor power permitted;
位相反転 / 位相損失 / voltage unbalance detected → relay de-energizes and opens, cutting off main power, with dry contacts available for PLC or audible-visual alarm signals.
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