Carrier TRANSICOLD Vector 8500 Operation & Service Manual Download

Page: 92 / 326

62-11640

4–12

4.10.3

ProductShield

ProductShield is a group of Configurations that work
together to allow improved operating efficiency while
providing customized product protection.
Each ProductShield setting allows the user to select an
ambient temperature range in which to operate. The
Minimum and Maximum range values can be set to
OFF, or the allowed value range.

a. ProductShield Econo

ProductShield Econo allows the microprocessor to
automatically switch from Start/Stop Operation to Con-
tinuous Operation or vice versa. This allows maximum
product protection while providing for power savings
when ambient temperature is in the preset range.

ProductShield Econo - Go to Start-Stop Operation

When the unit is set to Continuous Operation, Product-
Shield Econo allows the unit to run in Start/Stop Opera-
tion when:

• The ProductShield Econo Configuration is set to

GO TO S/S

AND

• The unit has run in Continuous Operation for a

minimum of either 15 minutes or the Minimum
Run Time Functional Parameter setting (which-
ever time is longer)

AND

• The ambient temperature falls within the pre-

programmed temperature range

AND

• The unit is not already running in ProductShield

Winter. (See Section c.)

The operator can also pre-program a maximum evapo-
rator coil temperature differential (delta-t) between the
return air and supply air temperatures as an additional
criteria for switching to Start/Stop Operation. The unit
must bring the delta-t below this setting before going to
Start/Stop Operation if this option is chosen.

NOTE

In ProductShield Econo: Go to Start/Stop,
the delta-t must be lower than the value
selected in order to enter Start/Stop.

Once the microprocessor detects that the above crite-
ria have been met, the unit will switch from Continuous
Operation to a Start/Stop Off Cycle for the MINIMUM
OFF TIME Functional Parameter setting. During the
Minimum Off Time, the RESTART OVERRIDE TEM-
PERATURE Functional Parameter setting can cause
the unit to restart to protect the load. After the Minimum
Off Time has expired the unit will return to Continuous
Operation when the return air temperature is more than
the configured perishable restart temperature away
from setpoint in the perishable range, or the configured
frozen restart temperature above setpoint in the frozen

range.
When the unit restarts, it will return to Continuous
Operation for a minimum of 15 minutes or the Minimum
Run Time Functional Parameter setting, whichever
time is longer. The original activation conditions must
then be met in order for the unit to return to Product-
Shield Econo: Start/Stop.

ProductShield Econo Go To Start/Stop Examples:

The following examples apply in situations where all
other Start/Stop conditions have been met.
Example 1 If the Minimum is set to 30°F (-1.1°C) and
the Maximum is set to 40°F (4.4°C) and the ambient air
temperature falls

between

these temperatures, the unit

operation can change to Econo Start/Stop.
Example 2 If the Minimum is set to 30°F (-1.1°C) and
the Maximum is set to OFF and the ambient air tem-
perature is

above

30°F (-1.1°C), the unit operation can

change to Econo Start/Stop.
Example 3 If the Minimum is set to OFF and the Max-
imum is set to 40°F (4.4°C) and the ambient air tem-
perature falls

below

40°F (1.7°C), the unit operation

can change to Econo Start/Stop.
Example 4 If both the Min and the Max are set to
OFF, unit operation can change to Econo Start/Stop at
any ambient temperature.

ProductShield Econo - Go to Continuous Operation

When the unit is set for Start/Stop, ProductShield
Econo allows the unit to run in Continuous Operation
when:

• ProductShield Econo configuration is set to GO

TO CONTINUOUS

AND

• The unit has run in Start/Stop Operation for a

minimum of 15 minutes OR the Minimum Run
Time, Functional Parameter setting (whichever
time is longer)

AND

• The ambient temperature falls

outside

the pre-

programmed temperature range

AND

• The unit is not already running in ProductShield

Winter. (See Section c.)

Once the microprocessor detects that the above crite-
ria have been met, the unit will switch from Start/Stop
to Continuous Operation for a minimum of 30 minutes.

After 30 minutes the unit will return to Start/Stop if the

ambient temperature enters the pre-programmed tem-
perature range.

NOTE

Delta-t logic is not used or available when Prod-
uctShield Econo - Go To Continuous is active.