Lennox International Inc. 505 - Manual (Page 4)

Page 4
EDA 01/06
Component Functions
Charge CompensatorĊThe charge compensator
(shown in figure 5) serves to maintain the proper amount of
refrigerant circulating in larger systems. [Some systems
do not require a charge compensator, but do require a simi-
lar kit to connect into the system (see Engineering Hand-
book)]
The charge compensator stores excess refrigerant when
the EDA coil is active and returns it to the system during
normal cooling or heating operations. When the EDA coil is
active, less charge is required to obtain the proper amount
of subcooling because of the additional coil surface and
the cooler air which passes over the EDA coil.
Check/Flow RestrictorĊThe check function of the
check/flow restrictor (shown in figure 2) prevents refriger-
ant from flowing into the inactive components during times
when the EDA coil is inactive. The flow restrictor controls
the rate of return of charge to the system from the charge
compensator and the EDA coil when the system changes
from "EDA coil active" to "EDA coil inactive."
Figure 2
Check/Flow Restrictor Operation
O−RING SEALS
CHECK/FLOW
RESTRICTOR
CHECK/FLOW
RESTRICTOR FLOATS IN
CHATLEFF CONNECTOR
GREATER
PRESSURE
EDA
UNIT
GREATER
PRESSURE
EDA
UNIT
FROM
VAPOR
LINE
TEE
FROM
VAPOR
LINE
TEE
Valve AssemblyĊThe first valve of the diverting valve as-
sembly (figure 3, E) directs the flow of refrigerant to either
bypass the EDA coil (EDA coil is inactive) or pass through
the EDA coil (EDA coil is active).The second valve (figure 3
F) directs the flow of refrigerant back to the liquid line when
the first valve (E) allows flow through the EDA coil. When
the EDA coil is inactive, the second valve (F) provides a
vent path to the suction line, draining the EDA coil and
charge compensator of liquid refrigerant.
Figure 3
EDA−024B
EDA Unit Parts Arrangement
EDA−036C EDA−060D
3−WAY DIVERTING VALVE ASSEMBLY
EDA COIL
3−WAY DIVERTING VALVE ASSEMBLY
A − Liquid Line From Outdoor Unit
B − Liquid Line to Indoor TXV
C − Check/Flow Restrictor to Vapor
Line Tee
A B C D A B C D A B C D
EDA COIL
EDA COIL
D − To Charge Compensator side connection (1/4" line must be brazed closed on systems that do not
require the installation of a charge compensator)
E − EDA inactive mode − bypasses the EDA EDA active mode − allows refrigerant flow through EDA
F − EDA inactive mode − vent path to suction line; EDA active mode − directs refrigerant flow back to
liquid line
E F E F
3−WAY DIVERTING VALVE ASSEMBLY
E F