Danfoss VACON and VLT FC Application guide

ENGINEERING TOMORROW

Functional Safety Application Guide

Encoder-less Safety Functions SLS, SSR using DOLD Frequency Monitor

VACON® and VLT® FC-series

vlt-drives.danfoss.com

Contents Functional Safety Application Guide

Contents

1 Introduction

1.1 Purpose

1.2 Scope

1.3 Abbreviations

2 Safety Functions SLS and SSR

3 SLS and SSR Implementation

3.1 Circuit Diagram

3.2 Safety Function Operation and Timing

3.2.1 Initial Conditions 11

3.2.2 Fault Handling 11

3.2.3 SLS Operation 11

3.2.4 SSR operation 11

3.3 Parameters and Conguration

4 Ordering Data for DOLD Components

4.1 Frequency Monitor

5 Functional Safety-related Data

5.1 SIL Calculation

Index

Introduction Encoder-less Safety Functions SLS, SSR using DOLD Frequency Monitor

1 Introduction

1.1 Purpose

This manual describes how to implement the safety functions Safely Limited Speed (SLS) or Safe Speed Range (SSR) using DOLD UH 6937 frequency monitor without encoder.

The DOLD module can be used with the following products:

VLT® HVAC Drive FC 102

•

VLT® Refrigeration Drive FC 103

•

VLT® AQUA Drive FC 202

•

VLT® Midi Drive FC 280

•

VLT® AutomationDrive FC 301

•

VLT® AutomationDrive FC 302

•

VACON® 100 Industrial

•

VACON® 100 Flow

•

VACON® NXP Liquid Cooled

•

VACON® NXP System Drive

•

VACON® NXP Air Cooled

•

VACON® NXP Common DC Bus

•

VACON® NXP Liquid Cooled Enclosed Drive

•

VACON® NXP Liquid Cooled Common DC Bus

•

Scope

1.2

This manual is intended for application designers, for realizing safe speed functions of frequency converters without encoder feedback, using an external frequency monitor.

Abbreviations

1.3

PL Performance Level

SIL Safety Integrity Level

SLS Safely Limited Speed

SSR Safe Speed Range

STO Safe Torque O

Table 1.1 List of Abbreviations

SLS limit

Speed

Time

130BF781.10

SSR upper limit

SSR lower limit

Speed

Time

130BF782.10

Safety Functions SLS and SS... Functional Safety Application Guide

2 Safety Functions SLS and SSR

The Safely Limited Speed (SLS) function monitors the speed to a set limit value without any encoder feedback, see Illustration 2.1. The frequency of the motor is measured and compared to the limit value. If the measured value is more than the set value, then the safety output relay is deactivated to trigger the STO function.

Illustration 2.1 SLS Function

The Safe Speed Range (SSR) function monitors the speed within a given range or outside a given range. See Illustration 2.2.

Monitoring within the given range:

If the frequency is within the given speed range, the STO signal is not active. If the measured frequency is outside the given speed range, the relay output triggers the STO function of the frequency converter.

Monitoring outside the given range:

If the frequency is outside the dened speed range, the STO signal is not active. If the measured frequency lies inside the limits, the relay output triggers the STO function of the frequency converter.

In the standard module variant 0, 1 of the following monitoring functions is selected:

Over frequency

•

Under frequency

•

Inside range

•

Outside range

•

The variant 1 module has extra selection inputs for selecting 4 frequency modes during the operation.

NOTICE

If the frequency converter does not have an integrated STO function, the relay outputs can be used to activate the motor contactors to cut o the power to the motor.

2 2

Illustration 2.2 SSR Function

SLS and SSR Implementation Encoder-less Safety Functions SLS, SSR using DOLD Frequency Monitor

3 SLS and SSR Implementation

The SLS safety function implementation is based on the STO function and the following safety-related components:

Frequency monitor (3rd party DOLD UH 6937)

•

The UH 6937 frequency module does not have safe inputs to activate and deactivate the safety functions. In variant 0, the module always monitors the frequency. The monitoring can only be muted by selecting the parameter in the display. In variant 1, there are 4 digital safe inputs available to select dierent frequency modes, and 1 of the combinations is the muting function.

Noise suppression

•

party DOLD LG 5130), optional

These lters are only required if there is measurement errors after complete installation.

Third-party functional safety system or fail-safe

•

PLC (≤ SIL2), optional

A fail-safe PLC is required to implement the safety logic based on the status of the relay outputs of a frequency module. One of the use cases is, that the relay output status is ignored as long as the safety door is locked for SLS speed. Once the door is opened, the safety relay output is used to activate the STO of the frequency converter for speed limit violations.

The circuit example in chapter 3.1 Circuit Diagram shows the DOLD UH 6937 used with a Danfoss frequency

converter FC-series or VACON® series.

The auxiliary voltage 24 V is connected to terminals A1–A2. Any 24 V PELV or SELV supply can be used. If no additional devices are supplied via terminal 12 or 13 (+24 V), A1 can be connected to terminal 12 or 13. A2 can be connected to terminal 20 (0 V).

lter for measuring relays (3

NOTICE

Separate wires in separate cables with spacing in between have to be used for each of the frequency inputs. When monitoring 3-phase AC voltages, these terminals have to be wired directly to the motor connection terminals.

WARNING

RISK OF DEATH AND SERIOUS INJURY

If external forces act on the motor, for example in case

of vertical axis (suspended loads) the motor must be equipped with extra measures for fall protection. For example, install extra mechanical brakes.

The noise lter (LG 5130) has 4 inductances connected in series in each path for the 3 phases (input L1/L2/L3). This provides broad band ltering up to high frequencies. If the PE is connected, a Y-capacitor connected to PE is activated and provides increased ltering (T-lter).

The noise lter is connected via its input terminals L1/L2/L3 to the frequency converter output and the frequency monitor device to the lter outputs L1’/L2’/L3’.

By connecting the noise lter between the frequency converter and the measuring frequency monitor device, the current owing via the coupling capacitances is reduced. The reduction happens because the lter elements create a rising impedance with a rising frequency. This prevents disturbance or damage on the connected device. Protection as shown in Illustration 3.5.

It is not mandatory to connect the PE to the frequency monitor device terminals, but it increases the lter eect.

Terminals E1a, E1b, E2L, E2H, E3L, and E3H form the measuring input. For low voltages (AC 8–280 V), the measuring voltage is connected to E1a–E2L and E1b–E3L. For higher voltages (AC 16–600 V ), the measuring voltage is connected to E1a–E2H and E1b–E3H.

When monitoring single-phase AC voltage, the terminals E1a–E2L or E1a–E2H should be connected directly to the frequency converter. The terminals E1b–E3L or E1b–E3H should be connected directly to the motor connection terminals.

Chapter 3.2 Safety Function Operation and Timing includes the SLS operation and timing.

Remove the jumper wire between control terminals 12, 37, 38 in the frequency converter.

-SF8

RESET

+FIELD

Ensure that the STO cables are shielded if they are longer than 20 m (65.6 ft) or outside the cabinet.

-TA1

VLT FC 280 Frequency

converter

PE/GND

GND

PE/GND

L1 L2 L3

-FC1 _

95(PE)

91(L1)

92(L2)

93(L3)98(W)

97(V)

96(U)

99(PE)

-U2

NSGAFÖU 1.8/3 kV BK min. 2.5 mm

(14 AWG)

-WD1

-MA1

M 3~

BN BK GY

U1 V1 W1

E1a E2L E2H E1b E3L E3H

14 23 24 A1+ A2 RES T1 T2 RF

4838

UH6937

-FC31

24 V DC 0 V DC

2 4 6

3 5

130BF784.10

SLS and SSR Implementation Functional Safety Application Guide

3.1 Circuit Diagram

Illustration 3.1 shows the UH 6937 Circuit diagram. The relay contacts 13–14 and 23–24 can be used as STO input to the frequency converter.

3 3

Illustration 3.1 FC 280 and UH 6937 Wiring Diagram

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