DOLD SL 5881 VARIMETER IMD Insulation Monitor Installation Guide

: June 3, 2024
: DOLD

Table of Contents

Installation / Monitoring Technique
Function Diagram
Function
Technical Data
Documents / Resources
- Read User Manual Online (PDF format)
- Download This Manual (PDF format)

VARIMETER IMD
Insulation Monitor
IL 5881, SL 5881
Translation of the original instructions

Installation / Monitoring Technique

Function Diagram

IL 5881/100, SL 5881/100; IL 5881, SL 5881

With reference to IEC/EN 61557-8 (see also section “Notes”)
For DC voltage systems up to 12 … 280 V
Wide voltage range of measuring input UN DC 12 … 280 V (on request DC 24 … 500 V with separate auxiliary supply, Measuring range 20 … 500 kΩ)
Adjustable tripping value RAL of 5 … 200 kΩ or 10 … 500 kΩ
Selective ground fault indication for L+ and L- allows fast fault finding
Without auxiliary supply
De-energized on trip
2 changeover contacts
Automatic or manual reset, programmable
With test and reset buttons
Connection for external test and reset button possible
Galvanic separated AC or DC auxiliary supply available as option
Adjustable time delay as option
2 models available:
IL 5881: 61 mm deep with terminals near to the bottom to be mounted in consumer units or industrial distribution systems according to DIN 43880
SL 5881: 98 mm deep with terminals near to the top to be mounted in cabinets with mounting plate and cable ducts
DIN rail or screw mounting
35 mm width

Approvals and Markings

Application

Monitoring of asymmetrical insulation resistance of ungrounded DC-voltage systems to earth.
For industrial and railway applications

Function

If the insulation resistance RE between L+ or L- to ground drops below the adjusted alarm value RAL (insulation failure) the corresponding red LED goes on and the output relay switches off (de-energized on trip). If the unit is on auto reset (bridge between LT-X1) and the insulation resistance gets better (RE rises), the insulation monitor switches on again with a certain hysteresis and the red LED goes off.
Without the bridge between LT-X1 the insulation monitor remains in faulty state even if the insulation resistance is back to normal. The location of the fault on L+ or L- is indicated on the corresponding LED (selective fault indication).
The reset is done by pressing the internal or external reset button or by disconnecting the auxiliary supply.
By activating the “Test” button internal or external an insulation failure can be simulated to test the function of the unit.
Indicators

Green LED “ON”:	On, when supply voltage connected
Red LED “RE+”:	On, when insulation fault detected (RE+< RAL) on L+
Red LED “RE-“:	On, when insulation fault detected (RE <RAL) on L-

Circuit Diagrams

Connection Terminals

Terminal designation	Signal description
A1	L / +
A2	N / –
L+, L-	Connection for monitored IT-systems
PE	Connection for protective conductor
PT, X1	Connection for external test button
LT, X1	Connections for external reset or manual and auto reset:

LT/X1 bridged: Hysteresis function
LT/X1 not bridged: Manual reset
11, 12, 14, 21, 22, 24| Changeover contact (insulation failure)

Notes
WARNING
Risk of electrocution!
Danger to life or risk of serious injuries.

Disconnect the system and device from the power supply and ensure they remain disconnected during electrical installation.
The terminals of the control input PT, LT1 und X1 have no galvanic separation to the measuring circuit L+/L- and are electrically connected together, therefore they have to be controlled by volt free contacts or bridge. These contacts ore bridges must provide a sufficient separation depending on the mains voltage on L+/L-.
No external potentials may be connected to external control terminals PT, LT1 und X1.

Attention!

Before checking insulation and voltage, disconnect the insulation monitor IL/SL 5881 from the power source!
In one voltage system only one insulation monitor can be used. This has to be observed when interconnecting two separate systems.
According to IEC/EN 61 557-8 insulation monitors must be able to monitor the isolation resistance of the IT-system including symmetric and none symmetric occurance of the isolation resistance. Because of the measuring principle with a resistor bridge (asymmetry principle) the insulation monitor IL/SL 5881 will not detect symmetric ground faults of L+ and L-. Also a voltfree (disconnected UN = 0V) system cannot be monitored.
If the monitoring of symmetrical insulation resistances in ungrounded DC systems is required, the RL 5881 insulation monitor, for example, is suitable.

Attention!

The IL/SL 5881 can be used in systems with high leakage capacity to ground. When the unit is adjusted to high alarm values a leakage capacity can create a pulse when switching the system on (short alarm pulse).
This happens at the following values:
IL / SL 5881: RAL = 200 kΩ: CE > 1 µF
IL / SL 5881: RAL = 50 kΩ: CE > 6 µF
IL / SL 5881: RAL = 20 kΩ: CE > 16 µF
IL / SL 5881/100: RAL = 500 kΩ: CE > 0.8 µF
IL / SL 5881/100: RAL = 200 kΩ: CE > 0.8 µF
IL / SL 5881/100: RAL = 50 kΩ: CE > 2.0 µF
IL / SL 5881/100: RAL = 20 kΩ: CE > 4.5 µF
An optional time delay (on request) could suppress this pulse.
On models with separate auxiliary supply the alarm state is not defined when the voltage drops below 3 V. To avoid false alarm an additional auxiliary relay should be used which is connected to the monitored voltage or the variant IL 5881.12/010 is used.
On the models with galvanic separation between DC auxiliary supply and measuring input, the supply (A1/A2) can be connected to the monitored voltage system (L+/L-). The voltage range of the auxiliary input must be noticed which is only 1.25 of UH while the measuring input always goes up to 280 V. If no auxiliary supply is available the model IL/SL 5881/100 (without auxiliary supply) can be used which takes the auxiliary supply from the monitored system (UH = UN = DC 12 … 280 V).

Technical Data

Auxiliary Circuit
(only at IL/SL 5881)

Auxiliary voltage UH:| AC 220 … 240 V, 380 … 415 V
DC 12 V, 24 V
DC 24 … 60 V
---|---
Voltage range:
AC:
DC:| 0.8 … 1.1 UH
0.9 … 1.25 UH
Frequency range (AC):| 45 … 400 Hz
Nominal consumption
AC:
DC:| Approx. 2 VA
Approx. 1 W

Measuring Circuit

| Standard| extended, on request
---|---|---
Nominal voltage UN at| |
≤ 5 % residual ripple:| DC 12 … 280 V| DC 24 … 500 V
≤ 48 % residual ripple:| DC 12 … 220 V|
Voltage range:| |
Alarm value RAL:| 1.) 5 … 200 kΩ| 20 … 500 kΩ
| 2.) 10 … 500 kΩ|
Setting RAL:| infinite setting| infinite setting
Internal DC resistance| 1.) each appr. 75 kΩ| each approx.
L+ and L- to PE:| 2.) each appr. 100 kΩ| 190 kΩ
Max. meas. current at PE (RE = 0):| 1.) UN / 75 kΩ
2.) UN / 100 kΩ| UN / 190 kΩ

Operate delay

RE
from ∞ to 0.9 RAL:| Approx. 0.8 s|
---|---|---
RE from ∞ to 0 kΩ:| Approx. 0.4 s|
Response inaccuracy:| ± 15 % + 1.5 kΩ| IEC 61557-8
Hysteresis
At RAL = 50 kΩ:| Approx. 10 … 15 %|
Time delay:| 0.5 … 20 s (variant)|

Output

Contacts:

General Data

Operating mode:	Continuous operation

Temperature range
Operation:| – 20 … + 60°C
Storage:| – 20 … + 60°C
Altitude:| ≤ 2000 m

Clearance and creepage distances

Rated impulse voltage / pollution degree between auxiliary supply| 4 kV / 2 at AC-auxiliary voltage| IEC 60664-1
---|---|---
Between measuring input connections (L+ / L- / PE):| 4 kV / 2| IEC 60664-1
Between auxiliary supply and measuring input
connections:| 4 kV / 2| IEC 60664-1
Input to output(contacts):| 6 kV / 2| IEC 60664-1

EMC

Electrostatic discharge:	8 kV (air)	IEC/EN 61000-4-2

Dimensions
Width x height x depth:

IL 5881:	35 x 90 x 61 mm
SL 5881:	35 x 90 x 98 mm

Classification to DIN EN 50155 for IL 5881

Vibration and
shock resistance:| Category 1, Class B| IEC/EN 61373
---|---|---
Ambient temperature:| T1 compliant
T2, T3 and TX with operational limitations
Protective coating of the PCB:| No

Standard Types
IL 5881.12/100 DC 12 … 280 V 5 … 200 kΩ
Article number: 0053805

Without auxiliary supply UH
Nominal voltage UN: DC 12 … 280 V
Adjustable alarm value RAL: 5 … 200 kΩ
Width: 35 mm

SL 5881.12/100 DC 12 … 280 V 5 … 200 kΩ
Article number: 0055168

Without auxiliary supply UH
Nominal voltage UN: DC 12 … 280 V
Adjustable alarm value RAL: 5 … 200 kΩ
Width: 35 mm

Variants

IL / SL 5881.12:	With auxiliary supply
IL / SL 5881.12/010	With auxiliary supply no alarm at UN < 3 V
IL / SL 5881.12/300	Without auxiliary supply

Nominal voltage UN DC 12 … 280 V closed circuit operation
Time delay 0.5 … 20 s
IL / SL 5881.12/800:| Special low resistance range for the threshold value with limitation of the
voltage range:
Article number:| 56910| 56911
---|---|---
Nominal voltage UN at ≤ 5 % residual ripple:| DC 12 … 110 V| DC 12 … 24 V
Voltage range:| 0.8 … 1.25 UN| 0.8 … 1.25 UN
Alarm value RAL:| 1 … 50 kΩ| 0.2 … 10 kΩ
Setting RAL:| infinite setting| infinite setting
Internal AC resistance
L+ and L- to PE:| each approx.
18.5 kΩ| each approx.
2.8 kΩ
Max. meas. current at PE (RE = 0):| UN / 18.5 kΩ| UN / 2.8 kΩ

Ordering example for variants

Accessories

ET 4086-0-2:| Additional clip for screw mounting
Article number: 0046578
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Connections Examples

Monitoring of an ungrounded system.
1) Auxiliary supply UH (A1-A2) can be taken from monitored voltage system. The range of the auxiliary supply input must be observed.
2) With bridge LT – X1: Automatic reset
Without bridge LT – X1: Manual reset, reset with button LT

Monitoring of an ungrounded system without auxiliary supply.
*2) With bridge LT – X1: Automatic reset
Without bridge LT – X1: Manual reset, reset with button LT

All technical data in this list relate to the state at the moment of edition. We reserve the right for technical improvements and changes at any time.

E. Dold & Söhne GmbH & Co. KG • D-78120 Furtwangen
Bregstraße 18 • Phone +49 7723 654-0 • Fax +49 7723 654356
dold-relays@dold.com • www.dold.com
17.02.22 en / 512A

Documents / Resources

| DOLD SL 5881 VARIMETER IMD Insulation Monitor [pdf] Installation Guide
IL 5881, SL 5881, SL 5881 VARIMETER IMD Insulation Monitor, VARIMETER IMD Insulation Monitor, VARIMETER IMD, Insulation Monitor
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