Yaskawa E7B Drive Bypass System - Manual (Page 44)

Yaskawa Electric America, Inc.
Installation Guide IG.E7B.02 Rev: 04-11
Date: 11-1-04 Page 42 of 46
BYPASS UNIT START UP PROCEDURE
(Please review “Bypass Start Up Preparation” on page 41)
The front control panel has a digital alpha/numeric display and keypad, in the upper portion, for Drive operation and
programming. The row of LEDs above the alpha/numeric display indicate Drive operational status. The REMOTE
SEQ and REF LEDs in this row are always lit in most Bypass unit applications of the E7 Drive. The row of LEDs
below the alpha/numeric display indicate the Drive menu that is presently active, for the E7B_ _ _T units. This infor-
mation is part of the LCD display for the E7B_ _ _Y units.
The lower portion of the front control panel displays the operating mode status via LEDs and controls the HAND/
OFF/AUTO functions for both the Drive and Bypass. The general rule for LED colors, in the lower portion of the
control panel, is:
Green = Normal Status
Amber = Abnormal Status
Red
= Fault Status
1. Before applying power, make sure that the following conditions are met:
• The VAV terminal unit dampers, in supply fan applications, are open to prevent duct flexing or damage
in a fullspeed, across the line starting situation.
• The electro-mechanical motor OverLoad Relay (OLR) (S10) is adjusted to equal the Full Load Amps
(FLA) valuefrom the motor nameplate.
The OLR is mounted to the contactor assembly or back panel (depending on rating), just above the Bypass
contactor. See Figure 1.17. Electrically on the output power side of the Bypass unit, the adjustable thermal
OLR provides overload protection for the motor in both the Drive and Bypass operating modes. The OLR is
set up in the factory to be a manual reset device, requiring operator attention if an overload trip-out is experi-
enced.
Fig 1.17 Typical Motor Overload and Contactors
OverLoad Relay
Bypass Contactor
Adjustment Dial
Reset Button