LEGRAND 1U, Руководство пользователя

Страница: 518 / 543

Janu
ary 201
9
518 Legrand PDU User Guide
Unbalanced Current Calculation
Unbalanced current information is available on 3-phase models only. This section explains how Legrand
PDU calculates the unbalanced current percentage.

Calculation:
1. Calculate the average current of all 3 lines.
Average current = (L1+L2+L3) / 3
2. Calculate each line's current unbalance by having each line current subtracted and divided with the
average current.
L1 current unbalance = (L1 - average current) / average current
L2 current unbalance = (L2 - average current) / average current
L3 current unbalance = (L3 - average current) / average current
3. Determine the maximum absolute value among three lines' current unbalance values.
Maximum (|L1 current unbalance|, |L2 current unbalance|, |L3 current unbalance|)
4. Convert the maximum value to a percentage.
Unbalanced load percent = 100 * maximum current unbalance

Example:

Each line's current:
L1 = 5.5 amps
L2 = 5.2 amps
L3 = 4.0 amps

Average current: (5.5+5.2+4.0) / 3 = 4.9 amps

L1 current unbalance: (5.5 - 4.9) / 4.9 = 0.1224

L2 current unbalance: (5.2 - 4.9) / 4.9 = 0.0612

L3 current unbalance: (4.0 - 4.9) / 4.9 = -0.1837

Maximum current unbalance:
Maximum (|0.1224|, |0.0612|, |-0.1837|) = 0.1837

Current unbalance converted to a percentage:
100 * (0.1837) = 18%
Ways to Probe Existing User Profiles
This section indicates available ways to query existing user accounts on the Legrand PDU.

With SNMP v3 activated, you get the "user unknown" error when the user name used to authenticate
does not exist.

Any user with the permission to view event rules can query all local existing users via JSON RPC.

Any user with the permission to view the event log may get information about existing users from the log
entries.

Any authenticated users can query currently-existing connection sessions, including
Webcam-Live-Preview sessions, which show a list of associated user names.