Siemens UL 489, Operating Instructions Manual, Page: 184 / 352

9 – 82
9.2.2.7 Connecting voltage transformers
The metering module ("Meter PLUS Function") can be set to expect 3W or 4W (LL/LG) connections and will correct the amplitude and phase
of the signal as necessary.
The parameters on the trip unit must be set as follows:
(1) VT Primary voltage (100 V ac ... 1200 V ac)
(2) VT Secondary voltage

(100 V/110 V/120 V)
(3) VT Connection

(Wye / LG, Delta / LL)
Three VTs must be used at all times.
All three VTs must be rated for the rated LL voltage (e.g. 480 V) and can have either 100 V / 110 V or 120 V secondary rated voltage.
DANGER
Hazardous voltage.

Will cause death, serious personal injury, or equipment damage.
Turn off and lock out all power supplying this equipment before working on this device.
Note: Required primary and secondary overcurrent protection (fusing) not shown for clarity.
to X8.8
to X8.7
to X8.6
to X8.5 L1
L2
L3
LN
120V/ 3
primary bus
configuration
VT primary
connection
VT primary
connection
3:4W System: Wye (L-N, L-G) Connection
V
L-L
(V
L-L
)/ 3
(V
L-L
)/ 3
Secondary Primary
(277V)
(69V)
(assuming 480V LL)
V
L-L
(480V)
120V
Metering VT Settings:
Delta/Wye : Delta
VT Primary: 480 (for instance)
VT Secondary: 120 (for instance)
Metering VT Settings:
Delta/Wye : Wye
VT Primary: 480 (for instance)
VT Secondary: 120 (for instance)
primary bus
configuration
69V
√
√ √
Secondary
to X8.8
to X8.7
to X8.6
to X8.5 L1
L2
L3
V
1-2
120V
V
2-3
V
3-1
Primary
V
L-L
3
:
3W System: Delta (L-L) Connection
Rotation: A-C-B
(assuming 480V LL)
(480V)
208V
Secondary
to X8.8
to X8.7
to X8.6
to X8.5 L1
L2
L3
V
1-2
120V
V
2-3
V
3-1
Primary
V
L-L
3
:
3W System: Delta (L-L) Connection
Rotation: A-B-C
(assuming 480V LL)
(480V)
208V