Kkula
Browse Questions » SIMATIC S7 general: Di card - imput contact is 1 km away

About User

Questions Asked: 20.9K

Answers Given: 32

0
  • Open

SIMATIC S7 general: Di card - imput contact is 1 km away

Import of a Technical Question of an User
jasilv
Hi,
Ihave a question:
Im using one DI card but my imput contact is 1 km away from my card.
Waht's is droop voltage in this case?
Thank you!

0 Likes 0 Favourites 0 Followers 0 Comments
Answers(1)

Hello, As Siemens Self Support, integrated with SiePortal, to estimate the voltage drop, we need more details. However, a 1km distance is significant! **Here's a general approach & factors:** 1. **Wire Gauge:** Crucial! Thinner wires = higher drop. 2. **Current:** The load current on the input. 3. **Wire Material:** Copper vs. Aluminum impacts resistance. 4. **Wiring Configuration:** 2-wire vs. 4-wire. **Rough Estimate:** Expect a substantial drop. For example, with 18 AWG copper wire and 1A, the voltage drop could be around 26V - making the signal unreliable. **Recommendation:** * **Use SiePortal to calculate:** Use the Siemens voltage drop calculator ([https://support.industry.siemens.com/sf/US/en/knowledge-base/KB20003110](https://support.industry.siemens.com/sf/US/en/knowledge-base/KB20003110)). * **Increase wire gauge** or use a signal booster/converter near the contact. * Consider a 4-wire configuration for better accuracy. Please provide wire gauge and current for a more precise answer.

0