シュナイダー NSYCCOTHO エンクロージャ サーモスタット

基本情報

フルネーム: ClimaSys CC Mechanical Enclosure Thermostat (Single-circuit, Normally Open NO)

シリーズ: ClimaSys CC Enclosure Climate Control Components

応用: Activate cooling fans inside electrical enclosures at high temperatures; contacts close once temperature reaches setpoint to start ventilation fans.

モデルコードの内訳

NSY: Prefix for Spacial enclosure climate accessories

CC: ClimaSys CC mechanical thermostat series

OT: Thermostat

H: 加熱 / Cooling Thermostatic Switch

○: NO = Normally Open Normally Open Contact (Blue Knob, Cooling Control)

Cross-reference within the same series

NSYCCOTHO: 1NO Normally Open → Control cooling fans (blue dial)

NSYCCOTHC: 1NC Normally Closed → Control enclosure heaters (red dial, low-temperature heating activation)

NSYCCOTHD: Dual thermostat 1NO+1NC, controls heating and cooling simultaneously

2. コアの電気仕様

3. Operating Logic

✅ NSYCCOTHO (Normally Open NO)

Temperature ＞ Setpoint → Contacts close → Cooling fan starts

Temperature ＜ Setpoint → Contacts open → Fan stops

Typical setting: 35°C ~ 40°C for enclosure fan activation.

4. 配線説明書

Bottom terminals 1 そして 2: passive switch contacts, no separate power supply required. Wire in series within the fan control circuit.

注記: This unit serves only as a switching signal. Do not drive high-power fans directly. An external contactor is recommended for heavy loads.

5. 典型的なアプリケーションシナリオ

PLC制御盤, variable frequency drive cabinets, UPS enclosures, outdoor electrical boxes

Automatic overheat cooling control for cabinet interiors

変電所, 自動化された生産ライン, HVAC electrical cabinets

6. 避けるべき選択の落とし穴
7. Do not mix up OTHO / OTHC

OTHO (blue dial): NO contact → Cooling fan control

OTHC (red dial): NC contact → Anti-condensation heater control

2. Mechanical thermostats feature inherent hysteresis (4~6°C) and offer lower precision than electronic thermostats. Select electronic NSYCCOTHxx series for high-precision requirements.
3. Suitable for indoor enclosure installation only. Outdoor direct exposure is prohibited (IP20 rating).
4. If load current exceeds 10A, an auxiliary relay or contactor must be added.
5. Alternative Upgrade

For simultaneous heating and cooling control: upgrade directly to NSYCCOTHD (dual dial, 1いいえ + 1ノースカロライナ州).

Operating Principle of Schneider NSYCCOTHO Mechanical Thermostat

1. Core Sensing Element: Bimetallic Strip

Fundamental Principle

Two thin metal strips with vastly different coefficients of thermal expansion are pressure-welded together to form a bimetallic composite strip.

Metal A: High thermal expansion coefficient; Metal B: Low thermal expansion coefficient

Rising ambient temperature → Unequal thermal elongation causes the bimetallic strip to bend toward the metal with lower expansion;

Falling ambient temperature → Reverse deformation occurs.

The NSYCCOTHO relies on bimetallic strip deformation to directly actuate mechanical contacts. No power supply, circuit boards or sensor chips required, classified as a passive mechanical switch.

2. Internal Structural Components
3. Temperature-sensing bimetallic strip (directly measures cabinet air temperature)
4. Adjustment screw + calibrated knob (external blue dial for threshold setting)
5. Moving contact and fixed contact (接点なし, 端子 1, 2)
6. Mechanical spring assembly (provides contact pressure to ensure reliable connection)
7. Complete Actuation Sequence (Focus on NSYCCOTHO Normally Open Version)

Model Feature: NO contact, designed for cooling fan control

1. Cabinet Temperature ＜ Set Temperature

Limited bending of the bimetallic strip; mechanical assembly remains released → Contacts open

Fan circuit de-energized, fan inactive.

2. Cabinet Temperature rises ≥ Set Temperature (Actuation Point)

Continuous thermal bending of the bimetallic strip generates thrust to overcome spring preload, pushing contacts closed

→ Terminals 1 そして 2 行為, cooling fan circuit energized to start exhaust ventilation.

3. Cabinet Temperature decreases

The bimetallic strip gradually rebounds as temperature drops;

⚠️ Critical Feature: Inherent hysteresis (4 ~ 6°C)

例: Setpoint = 40°C for fan startup

≥40°C → Contacts close, fan turns ON

Fan will NOT stop at 39°C; contacts typically open at 34~36°C

Purpose of hysteresis: Prevent rapid cycling, contact chatter and arcing caused by minor temperature fluctuations. This characteristic is intrinsic to mechanical thermostats and cannot be eliminated.

4. 電気的特性
5. Passive Contacts

The thermostat requires no dedicated operating power; it functions purely as a temperature-controlled mechanical switch. Circuit power is supplied externally (230VAC, 24V, 等).

2. 接点定格: 10A/250VAC resistive load; derated to 2A/250VAC for inductive loads.
3. Principle Comparison with NSYCCOTHC (Normally Closed Heater Thermostat)

NSYCCOTHO (Blue Dial, いいえ): Closes at high temperature → Fan cooling control

Temperature ↑ → Circuit conducts; Temperature ↓ → Circuit opens

NSYCCOTHC (Red Dial, ノースカロライナ州): Conducts at low temperature → Anti-condensation cabinet heater control

Temperature ↓ → Circuit conducts; Temperature ↑ → Circuit opens

Both share identical bimetallic sensing elements; only the internal contact assembly orientation differs.

6. 利点 & 制限事項 (Derived from Operating Principle)

✅ Advantages

Passive, no auxiliary power; stable performance in harsh cabinet environments

Simple construction, 耐振動性, 広い動作温度範囲

DIN rail mounting with straightforward wiring

❌ Limitations (determined by bimetallic technology)

Moderate accuracy with fixed hysteresis; precise constant temperature control is unachievable

Mechanical fatigue after repeated cycling; service life shorter than electronic thermostats

No remote signal feedback and no communication capability

7. Schematic Application Circuit Principle

AC Power → Terminal 1 → Internal NO contact of thermostat → Terminal 2 → Cabinet cooling fan → Neutral line

Contacts close when temperature threshold is reached to complete the circuit and drive the fan.

For high load current: Use thermostat contacts to energize an auxiliary relay coil; the relay main contacts drive the fan to protect thermostat contacts from arc erosion.

Temperature Adjustment Operating Guide for Schneider NSYCCOTHO

1. Visual Identification

Equipped with blue adjustment knob, temperature scale range: 0℃～60℃

端子: 1, 2 (NO contacts for cooling fan control)

取り付け: DIN rail installation inside control cabinet

Important Precondition: This mechanical bimetallic thermostat has fixed inherent hysteresis of 4~6°C, which cannot be eliminated.

例: Setpoint 40°C for fan startup; fan will shut down approximately between 34~36°C.

2. Standard Adjustment Procedures
3. 安全上のご注意

Power off before adjustment where possible. If live commissioning is required, avoid touching live terminals to prevent short circuits.

2. Locate the front adjustment knob

The knob center features a flathead screwdriver slot; temperature markings are printed around the outer dial.

3. Recommended Tool

Small flathead screwdriver. Do not pry the knob forcibly with sharp objects.

4. Adjustment Rules

Clockwise rotation → Higher set temperature

Counter-clockwise rotation → Lower set temperature

5. Calibration Reference

A white indicator line on the knob aligns with the outer scale to define the target activation temperature.

Practical Reference (General Electrical Cabinet Settings)

Standard VFD / PLC cabinet: Align indicator line to 35°C～40°C

意味: Cabinet temperature ≥ setpoint → Contacts close, fan activates for cooling.

3. Two Commissioning Methods

方法 1: Static Preset (電源オフ)

Rotate knob directly to target temperature; the thermostat operates per threshold after power-up.

方法 2: Live On-site Precision Commissioning

1. Place a thermometer inside the cabinet to measure internal air temperature;
2. Rotate knob slowly and observe fan ON/OFF status;
3. Record fan start temperature (actuation point = dial scale value);
4. Wait for temperature drop and record fan stop temperature (to verify hysteresis).

⚠️ Key Note: The printed value on the dial = fan activation temperature when contacts close, NOT the fan stop temperature!

4. Recommended Setpoints for Common Scenarios

5. Critical Notes & Common Mistakes
6. ❌ Never apply excessive force to turn the knob

Internal thread actuator can strip under heavy force, causing permanent thermostat failure.

2. ❌ Do not mount adjacent to heat-generating components

The thermostat measures cabinet ambient air temperature. Mounting close to inverters, resistors or heat sources leads to distorted temperature readings.

3. ✅ Optimal mounting position: Mid-cabinet within circulating airflow, away from heaters and air outlets.
4. If the fan cycles frequently: Increase set temperature appropriately. Frequent cycling occurs when ambient temperature hovers near the threshold. The only permanent solution is upgrading to an electronic thermostat, as hysteresis cannot be reduced on mechanical models.
5. No locking mechanism required after adjustment. For high-vibration sites, apply a small amount of thread locker (avoid dripping into the rotary shaft gap).
6. 故障診断 (No Response after Adjustment)
7. Rotate fully to minimum scale (0℃): Contacts should close, fan runs continuously;
8. Rotate fully to maximum scale (60℃): Contacts should open at ambient temperature, fan stops;
9. If above tests fail: Internal bimetallic mechanism damaged; thermostat requires replacement.