3-10 Receiving & Installation
MN715
AC Line Connections
Reduced Input Voltage Derating
All power ratings stated in Section 6 are for the stated nominal AC input
voltages (230, 460 or 575VAC). The power rating of the control must be reduced when
operating at a reduced input voltage. The amount of reduction is the ratio of the voltage
change.
Examples:
A 10hp, 230VAC control operating at 208VAC has a reduced power rating of 9.04hp.
10HP
208VAC
230VAC
+
9.04hp
Likewise, a 10hp, 460VAC control operating at 380VAC has a reduced power rating of
8.26hp.
10HP
380VAC
460VAC
+
8.26hp
To obtain the full output rating of 10hp in either case requires a 15hp Control.
380-400VAC Operation
Be sure all power to the control is disconnected before proceeding.
Size A, B, B2, C2 and D2 controls may be used directly with a 380-400VAC power
source, control modification is not necessary.
Size C, D, E, F and G controls all require modification for operation on the reduced line
voltage.
Tap change procedure (size C, D, E and F controls)
1.
Be sure drive operation is terminated and secured.
2.
Remove all power sources from the control. If power has been applied, wait at
least 5 minutes for bus capacitors to discharge.
3.
Remove or open the front cover and locate the control transformer (Figure 3-3).
4.
Remove the wire from terminal 5.
5.
Place the wire that was removed from terminal 5 onto terminal 4.
6.
Install or close the front cover.
Figure 3-3 Control Transformer Identification
