7
Failure Mode Comparison
Twin Guard Series
™
vs. Conventional Cascade Freezer
Event
Conventional Freezer No Back-Up
Conventional Freezer,
with Back-Up System
SANYO Twin Guard Series
™
Fan Failure
Freezer Fails
Freezer fails, CO
2
or LN
2
back-up
system offers short term protection
until contents can be removed and
repairs initiated
If one fan fails the second fan
automatically maintains energy
exchange
High Stage Compressor Failure
Freezer Fails
No high or low stage used. Two refrig-
eration systems, each with a separate
compressor, operate independently in
overlapping cycles during normal op-
eration. If one compressor fails internal
temperature is maintained indefinitely
at -65°C with backup compressor.
Optional LN
2
or CO
2
back-up system
offers additional protection
Low Stage Compressor Failure
Freezer Fails
Performance Chart, power-failure situation Normal operation and Twin Guard Series™ backup.
Reduced Power Consumption
The SANYO Twin Guard Series
™
Freezer
can be set for Normal or EcoMode
™
operation, depending on ambient tem-
perature and load. EcoMode
™
is recom-
mended for 90-95% of applications.
Although both refrigeration systems are
completely independent, EcoMode
™
establishes an overlapping cycle to
significantly reduce energy consump-
tion while optimizing interior uniformity
from top-to-bottom and front-to-back for
protection of high value materials.
Chamber temp. (°C)
Pull-up while a power failure
Single compressor operation
(kept at approx. -65°C)
Normal cycle operation (-80°C setting)
20
0
-20
-40
-60
-80
-100
0 1 2 3 4 5 6 7 8 9 10 11 12
(hour)
Chamber temp. (°C)
Central air temp. in cabinet
Ambient temp. 30°C, No-Load
20
0
40
-20
-40
-60
-80
-100
0 1 2 3 4 5 6 7 8 9 10 11 12
(hour)
Pull-up characteristics during power failure
Pull-down charateristics
Power Consumption Benefits
Model Number
MDF-U500VXC
MDF-U700VXC
Ambient Temperature
15°C
23°C
15°C
23°C
Normal Savings
-9.7%
-7.8%
-16.7%
-17.5%
EcoMode
™
Savings
-16.8%
-14.1%
-18.5%
-18.3%
