5
Battery Backup Unit (BBU) — Installation & Maintenance Manual Continued
Operation
The BBU is operated by a micro controller which per-
forms all of the functions pertaining to power man-
agement, battery monitoring and charging, and con-
trol of the Series 70 Servo NXT or On/Off Controller.
The BBU constantly monitors the incoming power. In
the normal mode of operation with power supplied to
the actuator, the batteries maintain a charge and are
in an offline mode. The power applied to the motor is
from the power supply, not the batteries.
When a power loss occurs, the BBU pauses for 5 seconds
and then reads the “Open/Close” fail position switch
setting. The BBU circuitry applies the stored power in
the batteries to move the valve or damper to the full
open or full closed position as initially designated by
the user. The BBU will allow up to one minute for the
actuator to attain the fail position. If the fail position
is reached before one minute, the BBU will detect the
loss of motor current and turn the power off to the
actuator to conserve battery power. The actuator re-
mains in this position until external power is restored
to the unit. When power is restored to the BBU, the
battery charge cycle commences.
Battery Status Indicator
The BBU has a bi-color red/green indicator on the
side of the battery enclosure to provide information
regarding the operation and battery status of the BBU.
Table 1 is a summary of the different indications.
Battery Charging
A battery charge cycle will commence upon the return
of power to the BBU. Charge cycles will require from a
few minutes to several hours depending upon the dis-
charged state of the battery, condition of the battery,
and ambient temperature. When the charge cycle is
complete, the batteries are held in a fully charged state
by applying a voltage which maintains the “Stand-by
Mode” of the battery.
Every 8 hours, a full charge cycle commences which
tests the condition of the batteries. This cycle will nor-
mally last a few seconds with batteries that are in good
condition. Batteries that require replacement will
require a longer period to complete the charge cycle.
After 12 hours, if the batteries cannot attain full
charge, the alarm relay is engaged to indicate that the
batteries require replacement. If your installing your
BBU to a S70 actuator, skip to page/section 8 (1.0). If
your BBU was shipped assembled to the actuator skip
to page/section 13 (4.4).
Indication Description
Solid Green The BBU is powered and the
batteries are fully charged.
Flashing Green The BBU is powered and the
batteries are charging.
Fast Flashing Red The BBU is not powered and the
actuator is seeking the fail position.
Slow Flashing Red The BBU is not powered and the
BBU is in low power stand-by.
Table 1 - Indicator Lamp Guide
To Next Page
Loading...