TOSHIBA VF-S15 frequency converter

Case 1 Mechanical Applications - STO VF-S15+Preventa XPS AF Module EN 954-1, ISO 13849-1, IEC 60204-1

Case 2 Mechanical Applications - SS1 VF-S15+Preventa XPS AV Module EN 954-1, ISO 13849-1, IEC 60204-1

Case 3 Process Application - STO VF-S15 (without additional modules) IEC 61508 (SIL 2/SIL 1)

2. Application restrictions

Prohibited scenarios: Applications where the load may accelerate after shutdown (such as vertical conveyors, elevators, and winches) pose safety hazards;

Function priority: STO has the highest priority. If STO is triggered, no torque operation will be executed first regardless of whether other functions are activated or not;

Prerequisite: The motor/frequency converter needs to be matched with the application capacity, and the speed loop and torque characteristics should be correctly configured. If necessary, dynamic braking resistors and other options should be provided.

Maintenance and compliance documents

1. Maintenance requirements

Preventive maintenance: It is recommended to check the safety function once a year (such as opening the protective door to verify whether the frequency converter stops according to the set safety function);

Component replacement: After replacing non VF-S15 components such as motors and emergency stop switches, acceptance testing must be performed again;

Capacitor maintenance: For products stored for more than 2 years, the capacitor needs to be gradually boosted and activated through a variable power supply (25% → 50% → 75% → 100% rated voltage, each for 30 minutes) before use.

2. Compliance documents

EU Declaration of Conformity: covering ATEX Directive, Machinery Directive, EMC Directive, to be executed in conjunction with the ATEX Guidelines and Safety Guidelines accompanying the product;

Declaration signing: Signed by both Technical Document Manager (Fredric Roussel, France) and Marketing Manager (Shin Okada, Japan), released in 2019;

Option compliance: Communication options (such as CANopen, PROFINET) and power options (such as EMC filters) require the use of original factory certified accessories (refer to the appendix options list).

Key issues

Question 1: Why is it necessary to use Preventa module for the STO function of VF-S15 frequency converter in mechanical applications? What is its core function?

Answer: Mechanical applications (compliant with IEC 60204-1 and the Machinery Directive) mandate the use of Preventa modules (such as XPS AF), with the following core reasons and functions:

Prevent accidental restart: If there is a power outage after the STO is activated, and the STO is mistakenly released during the power outage, the motor may automatically restart after the Preventa module is restored, posing a safety risk; The Preventa module can intercept this false trigger and ensure that manual operation is required to restart after power restoration, meeting the mechanical safety requirements of "reset does not trigger automatic start";

Multi device emergency stop coordination: If the system contains multiple BDMs (background debugging modules), the Preventa module provides multiple safety output interfaces, which can achieve synchronous emergency stop control of multiple devices and meet the safety linkage requirements of complex mechanical systems;

Compliance guarantee: Only with the Preventa module can the STO function fully comply with the requirements of EN 954-1 category 3 and ISO 13849-1 PL d, ensuring that mechanical applications pass safety certification.

(Note: For non mechanical scenarios such as process applications, if there is no need to prevent accidental restarts or multi device collaboration, the Preventa module is not necessary.). ）

Question 2: What is the core difference between the SS1 function (Safety Stop Class 1 Type C) of VF-S15 and the STO function? How to choose which function to use in practical applications?

Answer: The core differences and application selection logic between the two are as follows:

1、 Core difference

Comparison Dimension STO (Safe Torque Off) SS1 (Safe Stop Class 1, Type C)

The functional logic directly cuts off the motor torque, and the motor stops freely. First, it decelerates according to the set time, and then triggers STO after a delay

Stop category (IEC 60204-1) Category 0 (uncontrolled stop, fast but no deceleration) Category 1 (controlled stop, with deceleration process)

Applicable scenarios require emergency torque cut-off (such as personnel entering a dangerous area by mistake) and require smooth deceleration to avoid load impact (such as transporting fragile items)

Module dependent mechanical applications require Preventa modules, while other scenarios require the use of Preventa modules (such as XPS AV) to implement delay logic as needed

2、 Application selection principle

Select STO: When the scenario requires "immediately cutting off torque to avoid emergency risks" (such as operators accidentally touching dangerous areas or equipment operating abnormally), prioritize using STO to ensure that the motor quickly enters a torque free state;

Select SS1: When the scenario requires "smooth shutdown to protect the load or equipment" (such as conveying glass, precision parts, or avoiding mechanical impact during shutdown), use SS1 to achieve controlled shutdown through delayed deceleration and reduce the risk of load damage.