Leakage Resistance; Establishing The Leakage Resistance Of An Et 200S Station - Siemens SIMATIC ET 200S Operating Instructions Manual

Leakage resistance

C.1

Establishing the leakage resistance of an ET 200S station

Ohmic resistance
When establishing the leakage resistance for an ET 200S station (e.g. for a ground-fault
detector) you must take the ohmic resistance from the RC combination of the relevant
module into account:
Interface module
IM151-1 COMPACT
Power Module PM-E DC24V
PM-E DC24V/AC120/230V power module
Formula
With the following formula you can calculate the leakage resistance of an ET 200S station if
you protect all the aforementioned modules withone ground-fault detector:
R
ET200S
R
ET 200S
R
module
N
R
IM 151
R
IM 151
R
PM-E DC24V
If you protect the modules within an ET 200S station listed above with several ground-fault
detectors, you must determine the leakage resistance for every single ground-fault detector.
ET 200S
Operating Instructions, 08/2008, A5E00515771-06
Module
=
= Leakage resistance of the ET 200S station
= Leakage resistance of a module
= Number of power modules and the interface module in the ET 200S
station
= R = R
PM-E DC24V module
= Leakage resistance of the IM151-1 interface module
= Leakage resistance of power module PM-E DC24V
Ohmic resistance from RC network
10 MΩ (±5 %)
10 MΩ (±10 %)
10 MΩ (±5 %)
= 9.5 MΩ
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