3-2. Operating Procedures
circuit is removed, at which time operation returns to
This section contains the procedures required for starting
b. Parallel Operation. If a load greater than 50
and stopping the inverter in its various modes of operation
amperes (5 KVA) is anticipated, two inverters are to be
connected in parallel to provide the necessary power. A
3-3. Equipment Starting Procedures
Master/Slave cable assembly is provided to connect the
two units in parallel as shown in detail "B" of figure 2-2. In
Prior to performing the following turn-on procedure,
this mode of operation the inverter to which the MASTER
ensure that both DC and AC circuit breakers are set to
plug of the cable assembly is connected becomes the
OFF. Refer to paragraph 3-6 for the sequence of
controlling or master inverter and the unit which receives
operation to be followed in the event a circuit breaker trips
the SLAVE plug becomes the slave inverter. The 100
amp circuit breaker (user furnished) should be placed in
a. Single Inverter Starting Procedure.
the AC OUT lead as shown in B, figure 2-2, for best
paragraph 2-4 for electrical installation of a single inverter
in the system, and figure 3-1 for location of controls and
c. Operating Time. When there are two inverters, it
is recommended that they be used alternately to
accumulate equal operating times (as counted on the
Perform the Following in sequence
ELAPSED TIME meter); e.g., operate each inverter on
(1) Position DC circuit breaker to ON. Amber
3-5. Stopping Procedure
DC ON indicator lamp lights. Within 5 seconds the
Perform the following stopping procedures in the
cooling fans should be operating.
(2) Position AC circuit breaker to ON. Green
a. Non-Parallel Operation
AC ON indicator lamp lights.
(1) Position AC circuit breaker to OFF
b. Parallel Inverter Starting Procedure. Refer to
(2) Position DC circuit breaker to OFF; the
paragraph 2-4 for electrical installation of two inverters in
cooling fans stop operating.
parallel in a system, and figure 3-1 for location of controls
b. Parallel Operation
(1) Position the external 100 amp circuit
breaker to OFF.
Perform the following in sequence given.
(2) Position both AC circuit breakers to OFF.
(1) Position the DC circuit breaker of the
master inverter to ON. Amber DC ON indicator lamp
When the DC circuit breaker on the
lights. Within 5 seconds the cooling fans should be
master inverter is placed in the OFF
position, the DC circuit breaker of the
(2) Position the DC circuit breaker of the slave
slave inverter automatically trips off.
inverter to ON. Amber DC ON indicator lamp lights.
(3) Position the DC circuit breaker on the
Within 5 seconds the cooling fans should be operating.
master inverter to OFF and observe that the DC circuit
(3) Position the AC circuit breaker of the
breaker on the slave inverter trips off automatically and
master inverter to ON. Green AC ON indicator lamp
the cooling fans stop operating.
(4) Position the AC circuit breaker of the slave
3-6. Operation Under Abnormal Conditions
inverter to ON. Green AC ON indicator lamp lights.
Abnormal conditions which could affect the system
(5) Position the user-furnished external 100
include progressive and prolonged output overload,
ampere circuit breaker to ON.
overvoltage of the input voltage source above the
3-4. Equipment Operating Conditions
maximum specified, and undervoltage of the input
voltage source below the minimum specified.
a. Non-parallel Operation. During normal operation,
a. Progressive and prolonged output overloads
the DC VOLTAGE meter should indicate 104 to 141 vdc
cause the AC circuit breaker to trip. After the overload is
and the DC CURRENT meter should indicate up to 60
removed and the AC circuit breaker is reset by positioning
amp maximum. The AC VOLTAGE meter should indicate
to OFF and then to ON, normal operation can continue.
120 vac and the AC CURRENT meter should indicate 42
b. Overvoltage or undervoltage at the input causes
amp maximum (5000 VA). Because of the current-
the DC circuit breaker to trip. After the input voltage
limiting feature, a temporary short-circuit across the
condition is corrected, the inverter is reactivated by
output only causes the voltage to collapse until the short-
following the turn-on sequence given in paragraph 3-3.