1. Johdanto
The Walfront STVP-936 series automatic reset over-voltage, altage, and multi-function protector is a sophisticated monitoring and auxiliary device designed for three-phase four-wire power systems and electrical equipment. This device provides comprehensive protection by instantly cutting off the power supply to prevent damage to electrical equipment when conditions such as overvoltage, aliarvioitage, or overcurrent occur. Once the line voltage returns to normal, the protector automatically restores the power supply.
This protector integrates multiple functions including over-voltage, altage, over-current, three-phase current (voltage) unbalance, phase sequence (phase dislocation), and phase-break detection. It also features fault inquiry, voltmeter and ammeter functions, and the ability to restore factory settings. The clear LCD screen provides easy access to all functions and settings.
2. Turvallisuustiedot
VAROITUS: Installation and maintenance should only be performed by qualified electricians in accordance with local electrical codes and regulations. Failure to follow these instructions may result in electric shock, fire, or serious injury.
- Ensure power is disconnected before installation or any maintenance.
- Verify correct wiring connections for three-phase four-wire systems.
- Älä käytä laitetta, jos se näyttää vaurioituneelta.
- Pidä laite poissa kosteudesta ja äärimmäisistä lämpötiloista.
- The device is designed for indoor use within specified environmental conditions.
3. Tuote ohiview

Kuva 3.1: Etuosa view of the Walfront STVP-936 Voltage Suoja, jossa näkyy LCD-näyttö ja ohjauspainikkeet.
The STVP-936 is a compact device designed for DIN rail mounting. It features an LCD display for real-time voltage and current readings, as well as for navigating settings. Control buttons allow for adjustment of protection parameters.
Tärkeimmät ominaisuudet:
- Automatic reset function after fault clearance.
- Integrated protection against over-voltage, altage, ylivirta.
- Three-phase current (voltage) unbalance protection.
- Phase sequence (phase dislocation) and phase-break protection.
- Fault inquiry function.
- Built-in voltmeter and ammeter.
- Factory settings restoration option.
- Clear LCD display for easy monitoring and configuration.
4. Tekniset tiedot

Figure 4.1: Dimensions of the Walfront STVP-936 Voltage Suoja.
| Parametri | Arvo |
|---|---|
| Kohteen tyyppi | Säädettävä voltage Suoja |
| Materiaali | Muovi |
| Malli | STVP-936 |
| Rated Voltage (kolmivaiheinen nelijohtiminen) | 230 V / 400 V AC 50/60 Hz |
| Nykyinen luokitus | 1-50A adjustable (default 50A) |
| Overvoltage-arvoalue | 221V-300V-POIS (oletus 280V) |
| Overvoltage Palautumisarvoalue | 220V- (default 250V) |
| Overvoltage Action Time | 0.1 - 10 seconds (default 0.2 seconds) |
| Undervoltage-arvoalue | 219V-150V-POIS (oletus 160V) |
| Undervoltage Palautumisarvoalue | 220–151 V (oletusarvo 180 V) |
| Undervoltage Action Time | 0.1 - 10 seconds (default 0.2 seconds) |
| Overcurrent Action Time | 1 - 512 seconds (default 5 seconds) |
| Three-Phase Voltage Unbalance Value Range | 5–90 % alennus (oletus 25 %) |
| Phase Voitage Unbalance Action Time | 0.1 - 10 seconds (default 2.0 seconds) |
| Käynnistysviiveaika | 2 - 255 seconds (default 2 seconds) |
| Viankorjausviive | 2 - 512 seconds (default 60 seconds) |
| Virrankulutus | ≤3 VA |
| Näyttötila | LCD |
| Electrical Isolation Strength | >2000VAC, pulse 2.5KV 1.2/50μS |
| Työympäristön lämpötila | -20 ℃ ~ 50 ℃ |
| Työympäristön kosteus | < 85% |
| Working Environment Altitude | Enintään 2000 metriä |
| Arvioidut mitat (P x L x K) | 70 x 95 x 65 mm (2.8 x 3.7 x 2.6 tuumaa) |
| Tuotteen paino | 13.5 unssia |
5. Asennus ja asennus
The Walfront STVP-936 is designed for DIN rail mounting within an electrical enclosure. Ensure the enclosure provides adequate ventilation and protection from environmental factors.

Kuva 5.1: Etuosa view showing the 'IN' (input) and 'OUT' (output) terminals for wiring.
Johdotusohjeet:
- Virran katkaisu: Before beginning any wiring, ensure that the main power supply to the circuit is completely disconnected and locked out to prevent accidental re-energization.
- Asennus: Mount the STVP-936 onto a standard DIN rail securely.
- Input Wiring (IN terminals):
- Connect the incoming three-phase power lines (L1, L2, L3) and the Neutral line (N) to the corresponding 'IN' terminals at the top of the device.
- Varmista, että kaikki liitännät ovat tiukat ja turvalliset, jotta vältetään löysiä kontakteja ja ylikuumenemista.
- Output Wiring (OUT terminals):
- Connect the protected load's three-phase power lines (L1, L2, L3) and the Neutral line (N) to the corresponding 'OUT' terminals at the bottom of the device.
- Verify that the load's current requirements do not exceed the device's maximum current rating (50A for this model).
- Maadoitus: Ensure proper grounding of the electrical system as per local codes.
- Vahvistus: Tarkista kaikkien johtojen liitännät ja niiden kireys ennen virran kytkemistä takaisin päälle.

Kuva 5.2: Ylhäältä alas view illustrating the terminal block layout for wiring connections.
6. Käyttöohjeet
After successful installation and power-up, the device's LCD will display real-time voltage and current readings. The device is pre-configured with default settings, but these can be adjusted to suit specific application requirements.

Figure 6.1: Close-up of the LCD display and control buttons (SET, Up, Down).
Näyttö ja säätimet:
- LCD-näyttö: Näyttää reaaliaikaisen äänenvoimakkuudentage (V), current (A), and various protection parameters during configuration.
- SET -painike: Used to enter the setting mode and confirm parameter changes.
- Ylös/alas -painikkeet: Used to navigate through settings and adjust parameter values.
Parametrien säätäminen:
- Paina ja pidä painettuna SARJA button for a few seconds to enter the parameter setting mode.
- Käytä Up ja Alas buttons to scroll through the different adjustable parameters (e.g., Overvoltage Value, Undervoltage Value, Overcurrent Action Time, etc.).
- Kun haluttu parametri tulee näkyviin, paina SARJA button briefly to select it for adjustment.
- Käytä Up ja Alas buttons to change the value of the selected parameter.
- Paina SARJA button again to confirm the new value and move to the next parameter, or to exit the setting mode if no further changes are needed.
- If no buttons are pressed for a certain period, the device may automatically exit the setting mode and save changes.
Refer to the Specifications section (Section 4) for the default values and adjustable ranges of each parameter.
Fault Inquiry and Reset:
- The device automatically detects faults and disconnects power. The LCD will typically display the type of fault.
- After a fault condition clears and the recovery delay time (default 60 seconds) has passed, the device will automatically reset and restore power.
- To inquire about past faults, consult the device's specific menu options using the SET and Up/Down buttons.
- To restore factory settings, there is usually a specific sequence or menu option. Refer to the on-screen prompts or a more detailed manufacturer's guide if available.
7. Huolto
The Walfront STVP-936 Voltage Protector is designed for minimal maintenance. However, regular checks can ensure optimal performance and longevity.
- Silmämääräinen tarkastus: Tarkista laite säännöllisesti mahdollisten fyysisten vaurioiden, värinmuutosten tai löysien liitosten varalta.
- Puhdistus: Pidä laite puhtaana ja pölyttömänä. Käytä puhdistukseen kuivaa, pehmeää liinaa. Älä käytä nestemäisiä puhdistusaineita tai liuottimia.
- Yhteyden tarkistukset: Ensure all wiring connections remain tight and secure. Loose connections can lead to overheating and device malfunction.
- Ympäristöolosuhteet: Varmista, että käyttöympäristö pysyy määritetyissä lämpötila- ja kosteusrajoissa.
- Toimivuustesti: If possible and safe to do so, periodically test the protection functions by simulating a fault condition (e.g., temporarily reducing voltage if a test setup is available) to ensure the device responds correctly. This should only be done by qualified personnel.
Älä yritä avata tai korjata laitetta itse. Jätä kaikki huoltotyöt pätevän henkilöstön tehtäväksi.
8. Vianmääritys
Tässä osiossa on ohjeita yleisiin ongelmiin. Ongelmissa, joita ei ole lueteltu tässä, ota yhteyttä tekniseen tukeen.
| Ongelma | Mahdollinen syy | Ratkaisu |
|---|---|---|
| Laite ei käynnisty. | Ei syöttövirtaa; väärä johdotus; sisäinen vika. | Check main power supply. Verify input wiring (L1, L2, L3, N). If power is present and wiring is correct, the device may be faulty. |
| Laite laukeaa usein. | Voitage fluctuations (over/under); overcurrent condition; phase unbalance; incorrect settings. | Monitor line voltage and current. Check load for overcurrent. Verify protection parameter settings (overvoltage, aliarvioitage, overcurrent, unbalance thresholds). Adjust settings if necessary, ensuring they are appropriate for your system. |
| Device does not reset after fault clears. | Fault condition still present; recovery delay time not elapsed; internal fault. | Ensure the fault condition (e.g., overvoltage) has genuinely cleared. Wait for the configured failure recovery delay time to elapse. If the issue persists, power cycle the device (if safe) or contact support. |
| LCD-näyttö on tyhjä tai epäsäännöllinen. | No power; display fault; internal malfunction. | Check power supply. If power is present, try power cycling the device. If the problem persists, the device may require servicing. |
| Asetuksia ei voi säätää. | Incorrect button sequence; device locked. | Ensure you are pressing and holding the SET button correctly to enter setting mode. Follow the operating instructions precisely. |
9. Takuu ja tuki
Specific warranty information for the Walfront STVP-936 Voltage Protector is not provided in this manual. Please refer to the product packaging, your purchase documentation, or contact your retailer or Walfront customer service for details regarding warranty coverage and terms.
For technical support, troubleshooting assistance beyond this manual, or inquiries about replacement parts, please contact Walfront customer support through their official websivustoa tai ostoksesi yhteydessä annettuja yhteystietoja.