MASTER CONTROL SYSTEMS, INC.
REGULATED TWO RATE
FLOAT EQUALIZE
BATTERY CHARGER
This Charger has been specifically designed for recharging and maintaining engine starting batteries. It
will carry continuous or intermittent loads up to 100%/o of the charging rate.
These Chargers Provide:
· Automatic Float operation -output is
regulated to meet battery demand.
· A.C. Line Voltage Compensation.
· D.C. Voltage Regulation.
· Two Rate, Float-equalize toggle switch.
· Built-in Crank disconnect relay.
· Complete Solid State Control.
· Output Voltmeter and Ammeter.
CHARGER PERFORMANCE SPECIFICATIONS
FOR MBC8 MODELS, 12 and 24 Volt Nominal Voltage,
and 5 and 10 Ampere Rated Current.
INPUT LINE REQUIREMENTS: Nominal 117V. A.C. at
60 Hertz, Range of input voltage: 105-125V. A.C.
RECOMMENDED BATTERY CAPACITY: 5.0 to 23.0
Times rated current.
The following specifications apply at 117-125V. A.C.
input at 25C in either mode.
OUTPUT CURRENT: Unit will deliver at least rated
current into a fully discharged battery.
OUTPUT VOLTAGE LIMITS: Nominal Value (Factory Set).
BATTERY TYPE: LA (1.275 S.G.) FL (1.220 S.G.) NC (High Rate)
EQUALIZE: 2.42 V/Cell
2.29 V/Cell
1.55 V/Cell
FLOAT:
2.25 V/Cell
2.17 V/Cell
1.40 V/Cell
MODE SWITCHING: Front - Panel Toggle Switch.
VOLTAGE REGULATION - LOAD: ± 1.0%o Maximum - No Load to
Full Load (Float Mode).
VOLTAGE REGULATION - LINE: ± 1.0% Maximum for 10% Line
Change.
OPEN CIRCUIT LEAKAGE: 50mA Maximum.
OUTPUT DRAIN (A.C. INPUT OFF): 10mA Maximum.
OUTPUT TERMINAL VOLTAGE FOR CHARGER SHUTDOWN
(WITH SHUTDOWN OPTION): + 4.0 Volts Maximum.
Although designed especially for use with engine starting
batteries, the MBC8 is a true, two rate float charger and
can be used on other applications not requiring the
precision output regulation of the Master Controls Model
MBC7 or the automatic high recharge capability of the
MBC6.
This charger will carry external loads up to 100% of its
rating. In order to prevent extremely high external loads
(such as engine cranking) from overloading the charger,
a built-in crank disconnect relay is provided. Under no
load conditions, when the battery is fully charged, and
with the charger in the float mode, only enough current
will be supplied to replace the power lost through the
internal leakage of the battery. This keeps gassing and
water consumption to an absolute minimum.
When batteries are charged by the float method, the
battery
has
a
tendency
to
develop
differences
(inequalities) in the charge level among the individual
cells. This condition can be corrected by applying an
"equalizing" charge at periodic intervals. This is
accomplished by raising the charger output voltage by
several tenths of a volt per cell for a specified time. A
manual toggle switch is provided for this purpose.
All charge controls are factory preset so as to provide
proper operation on the particular type of battery.
LOW AND HIGH VOLTAGE ALARMS
Master Control's low voltage alarm Option (LCA)
provides a set of SPDT dry contacts rated for 10 amps
@ 115 V. A.C. The alarm set point is factory-adjusted to
a voltage set point which represents an open circuit
battery that is 25°% to 50% discharged. Factory-
adjusted for the particular battery type involved, it
requires no field adjustments. In order to prevent false
actuation of the alarm during high battery load
conditions, a built-in time delay of approximately 15
seconds is provided.
High voltage alarm Option (HCA) is also available. It will
detect abnormally high charge rates due to charger
failure. The alarm set point is factory-adjusted to a
voltage slightly higher than the charger's normal output.
Construction Features:
A.C. circuit breaker and D.C. Fuse is provided
All semiconductors are silicon and hermetically
sealed
Modular construction (Plug-in printed circuit
regulator board)
Float and equalize voltage levels are factory preset
for the specific battery type
No transformer tap settings are required
Output is completely isolated from A.C. power
Bulletin 474-2
