Emerson 400518-01 - Manual (Page 24)

12
Safety Information Product Overview Installation Diagnostics
Options and
Accessories
Specification
Figure 8: Earth Grounded Delta Distribution Transformer, 240 Vac 3 Ø
Figure 9: Three Phase Delta (with mid-phase GND) Distribution,
120 Vac split/240 Vac 3Ø supply
AC Supplies Requiring Transformers
If the distribution transformer is configured as shown in the figures below, an isolation transformer is required.
If an isolation transformer is used between the power distribution point and the drives, the transformer secondary
must be grounded for safety reasons as shown in the figures below.
DISTRIBUTION PANEL
SECONDARY
EARTH
GROUND
(Protective Earth)
L1
(N)
L2
L3
PE
230 Vac
No Fuse
To Fusing and
Drive Terminals
NOTE: For single phase drives using lines L1 & L2 or L1 & L3, only one fuse is
required on the high leg (L2 or L3). Lines L2 & L3 may be used to balance
the load, requiring two fuses.
DISTRIBUTION PANEL
SECONDARY
EARTH
GROUND
(Protective Earth)
Used only for 120 Vac operation
with L1 or L2.
L2
L1
L3
PE
N
Typ. 240 Vac
NOTE: L3 is a high leg, 208 Vac from Neutral/PE.
For single phase drives it is best to use lines L1 and L2.
L1 & L3 or L2 & L3 maybe used to balance loads.