# Automatic Phase Switch FF PF-451 for Use with Contactors

**URL:** https://aio.lv/en/product--ff-pf-451--10921602
**Data updated:** 2026-03-20 09:47 (EET)
**Category:** Control Systems
**Manufacturer:** FF
**Manufacturer code:** PF-451
**EAN:** 5908312594031
**Warranty:** 2 Years
**Availability:** Available for order
**Price:** 92.49 €
**Prices and availability valid until:** 2026-07-07 23:59
**Price without VAT (21%):** 76.44 EUR
**Can be purchased by legal entities:** Yes (invoice)
**Buy:** https://aio.lv/en/product--ff-pf-451--10921602

## Delivery options

| Delivery method | Delivery time | Cost |
|---|---|---|
| Office pickup (2b. Kengaraga str., Riga, Latvia, LV-1063) | 01.07.2026 | free |
| Pickup points | 06.07.2026 | 1.99 EUR |
| Courier delivery to door | 06.07.2026 | 4.99 EUR |

## Summary description

FF PF-451 is an automatic phase switch designed to cooperate with contactors. It monitors supply phases and switches between them to ensure power continuity for three-phase systems. Intended for industrial and commercial electrical installations, it helps protect motors and equipment from phase failure or imbalance by enabling automatic changeover to an available phase.

## Long description

FF PF-451 is an automatic phase switch designed to work together with contactors to maintain power continuity in three-phase electrical systems. It continuously monitors the three supply phases and activates an automatic changeover to an available phase if one phase fails or drops below acceptable voltage, reducing the risk of equipment downtime. The device is intended for use in industrial and commercial electrical installations where reliable phase supervision and automatic switching are required to protect motors, pumps, compressors and other three-phase loads.
Advantages
The FF PF-451 provides automatic detection of phase failure and seamless switching through contactor control, minimizing interruption to connected equipment. Its integration with external contactors allows flexible installation in existing switchgear and motor control circuits. The unit’s design prioritizes electrical safety and functional reliability by ensuring that switching occurs only when a suitable phase is detected, helping to prevent single-phasing and potential motor damage.
Suitable for
Motor protection and control in industrial machinery
Pumps and compressors requiring continuous three-phase supply
Commercial HVAC and ventilation systems
Backup power changeover schemes and phase monitoring in switchboards
Key specifications
Function: automatic monitoring and transfer between supply phases via contactor activation
Application: three-phase electrical systems for industrial and commercial installations
Compatibility: designed to operate in conjunction with external contactors for load switching
Protection purpose: reduces risk of motor damage caused by phase loss or imbalance
Operation: automatic changeover when a healthy phase is available; prevents switching to faulty or undervoltage phases
How to use
Install the FF PF-451 in the control circuit of the distribution board or motor starter so it can monitor incoming phase voltages and drive the appropriate contactors. Connect the unit’s monitoring inputs to the three supply phases and wire its control outputs to the contactor coils following the manufacturer’s wiring diagrams and local electrical standards. After installation, verify proper operation by simulating a phase loss and confirming that the contactors switch to an available phase only when voltage and phase sequence conditions are met. Ensure all wiring and commissioning are performed by a qualified electrician.
Usage recommendations
Use the FF PF-451 with contactors rated for the intended load and ensure coordination between protection devices. Regularly inspect connections and test phase changeover functionality as part of preventive maintenance to maintain reliable operation and to protect motors and three-phase equipment from phase-related faults.

## FAQ

### How much does the Automatic Phase Switch FF PF-451 cost, and is it available for purchase?

The price is 92.49 € (valid at the time of publication and already includes all taxes). The item is available for order — 8 pcs. are in stock, and you can place your purchase right now with delivery across Latvia and Europe or choose pickup at the Riga collection point. We offer favorable purchase terms, including the option to split the payment into convenient monthly installments. Availability and price are updated in real time, so we recommend placing your order in advance.

### If I order this product today, when will I receive my order?

If you place your order today, delivery will be as fast and convenient as possible. You will be able to pick up your order on 01.07.2026 at the Riga pickup point or choose delivery across Latvia and Europe. We carefully inspect every purchase and pack it securely for safe transportation.

### What payment options are available?

AiO.lv offers several payment methods: Bank transfer, Bank cards on-line, Apple Pay, Google Pay, Installment. All transactions are 100% secure and encrypted.

### Can Automatic Phase Switch FF PF-451 be purchased with a lease?

Yes, the purchase is available both on credit and with an interest-free installment plan. Learn more about installments and credit options: https://aio.lv/en/payment#b3

### Can this product be purchased for a company (with VAT)?

Yes. AiO.lv works with legal entities in Latvia and across Europe. The product price already includes VAT. For certain product categories, as well as for companies from other EU countries with a valid VAT number, a 0% VAT rate may apply. We issue the invoice immediately after the order is placed, support electronic BIS invoices, and automatically generate all necessary accounting documents. You can complete the purchase for a company online — simply select the company profile and choose bank transfer as the payment method during checkout.

### What is the warranty period?

All FF products come with an official 2 Years warranty. It covers all manufacturing defects and malfunctions that may occur during use. The warranty is valid at all authorized FF service centers and through AiO.lv

### Can the product be returned after purchase?

Yes, you can return the product within 14 days of purchase if you bought it as a consumer (not a legal entity). Returns are possible without giving any reason — the main condition is that the product retains its original appearance and full set of accessories. We will make the process as simple and convenient as possible: just contact our customer support team, and we will help you arrange the return.

### Where should I contact for warranty service?

For warranty-related questions you can contact the AiO.lv (SIA VSPRO) customer support team. More information about warranty service: https://aio.lv/en/warranty

## Image

https://aio.lv/img/cache/product/10921602/61140998_large.webp