Energy Management; Circuit Protection; Energy Management With Three Hour Averaging; Controlled Loads - Airstream TOMMY BAHAMA 2017 Owner's Manual

Interior

Energy Management

The ENERGY MANAGEMENT SYSTEM controls
120-volt operated circuits to help keep the total 120-
volt current draw to less than 30 amps� These circuits
may be any type load, but are typically heavier loads,
those whose use can be "postponed" until a time when
current is available for their use�

Circuit Protection

Circuit protection for ALL the 120-VAC loads is offered
by standard, resetable circuit breakers, provided by
Airstream� There are four positions available for circuit
breakers� These may be single or dual units� Airstream
uses both single and dual breakers as needed
according to the options ordered on a unit� One of
these breakers (MAIN) is a 30-amp unit that acts as the
main breaker for the entire system� The 120-volt power
is brought into the box from either a shoreline outlet,
generator, or the inverter can be used to feed circuit
4 only� The line side of this cable is fed through the
magnetically coupled current transformer to the Main
breaker� This breaker back-feeds power into the circuit
breaker bus bar to feed power to the branch breakers�
All the 120-volt loads in the touring coach are fed from
the branch breakers�
The 120-volt Distribution Panel on the front of the
power center contains the main breaker and the
branch circuit breakers for your touring coach� The
120-volt circuits may be turned "on" by putting their
breaker switch up to the on position or "off" by flipping
the switch down to the off position� If a circuit is over
loaded or an open (short) circuit occurs, a branch
breaker will "kick" out� To reactivate the circuit, try
to reset the breaker switch� To reset the tripped GFI
breaker push the handle down slightly to off then lift
up to on. If the breaker kicks out again, a qualified
electrical service technician should trouble shoot the
circuit� Each panel is labeled with the components
powered by individual circuits�
Refer to to Ground Fault Circuit Interrupter and GFCI
Breaker Test in this section for more information�
Energy Management with Three Hour
Averaging
The current entering the main circuit breaker is routed
through a sensor� This sensor measures the current
flowing through the main breaker, which is the total
amount being drawn by all the 120-volt circuits in the
touring coach� When this current exceeds 30 amps,
the EMS will turn off the controlled loads in an effort
to bring the total current to the limit of the incoming
service�
5-12
The ENERGY MANAGEMENT SYSTEM limits the
average current entering the main circuit breaker over
a three-hour period to 80 percent of the 30-amp service
rating� Therefore, if the average current entering
the main service breaker over a three hour period
exceeds 80 percent of 30 amps (24 amps) the 30A
Smart EMS will automatically change the service limit
to 80 percent� Correspondingly, the 30A Smart EMS
will restore the service limit to the full 30-amp value
when the average current drops below 80 percent of
the 30-amp rating� When the lowered service limits
are enabled, the decimal point in the lower right-hand
corner of the Load Meter on the Display module will be lit�
In addition, this ENERGY MANAGEMENT SYSTEM
feature is used when the generator is the power source
to prevent the generator's circuit breaker from tripping
due to an overload. The Control Module is configured
to enable the feature using the configuration dip
switches�

Controlled Loads

The system offers control of up to four 120-VAC
powered loads� Loads that are controlled are
connected to one of the relay circuits of the EMS�
There are five total control relays in the EMS. Only four
of these can be used in a given application�

Operation

In operation, when 120 VAC and 12 VDC are initially
applied, the system will energize the relays at one
second intervals, closing the normally open contacts
on each of the five relays while monitoring the total
current� If the total should exceed the service limit, the
system will turn off the last load that was turned on� As
it does this, it calculates the amount of current that was
removed, which is the value for that load� This value
is placed in memory� The system has "learned" the
amount of current that particular appliance draws� This
feature compensates for the difference in current draw
over a range of line voltage and ambient temperature,
by relearning the load each time it is turned off�
The system now waits until the total current is lower
than the service limit, by the amount in memory, before
it will turn that load back on� This ensures that there is
sufficient current to operate the load.
2017 Tommy Bahama TC