MARVEL Scientific 8CARM - Manual (Page 19)

temperature alarm will activate at 9°C = (4 [set temperature] + 3
[Ahi] + 2 [hysteresis])
5) Relative Low Temperature Alarm (ALO): The
number of degrees C colder relative to set tem
perature that will initiate a low temperature
alarm. Once the compartment temperature exceeds the low
temperature alarm value, the control will delay AdL minutes
before initiating the alarm. See Alarm Delay section below for
instructions to set alarm delay. While ALo is displayed on the
screen, press and hold SET key to view the value of ALo. To
adjust the value, continue to hold SET then use the WARMER
and COLDER keys until the desired value is shown on the screen.
Release the SET key to confirm the new setting. Factory default
value for ALo is -2.0°C.
Note: Setting ALo = 0 will disable the low temperature alarm.
No hysteresis value is added to ALo. For example, let set tem-
perature = 4°C, and ALo = -3. The low temperature alarm will
activates at 1°C = (4 [set temperature] + -3 [ALo])
6) Alarm Delay (AdL): The number of minutes the
compartment temperature must be outside the
range specified by Ahi and ALo before a tempera-
ture alarm activates. While AdL is shown on the screen, press
and hold SET key to view the value of AdL. To adjust the value,
continue to hold SET then use the WARMER and COLDER keys
until the desired value is shown on the screen. Release SET key
to confirm the new setting. Factory default value for AdL is 60
minutes.
7) Total Operating Time of the Condenser Since
the Last Cleaning (cnd): The operating time of
the condenser since the last cleaning. The control
monitors the operating time of the condenser fan to determine
when the condenser is in need of being cleaned. While cnd is
displayed on the screen, press and hold SET key to view the value
of cnd. The value shown is the number of weeks the condenser
has been operating. To reset cnd, continue to hold the SET key
then press and release the ON/OFF key.
When the control recommends the condenser be cleaned, a
reminder will be displayed on the screen (see Alarm Codes.) To
clear the alarm code, reset the value in cnd following the instruc-
tions printed above.
8) Keypad Lockout Feature (Loc): This feature is
used to prevent incidental changes to the set
temperature, or accidentally turning the unit off.
While Loc is displayed on the screen, press and hold the SET key.
If “No” is displayed, Lockout feature is off, and all
keys are enabled. If “Yes” is displayed, Lockout fea-
ture is ON. The ability to turn the unit on and off, as well as the
ability to adjust set temperature will be disabled. To change the
keypad lockout setting, continue to hold the SET key, then use
the WARMER and COLDER keys to set the desired value.
APPENDIX A, ADDITIONAL MICROSENTRY™ FEATURES
Information Menu / Lockout Key
To access the information menu, press the SET key, and immedi-
ately release it.
In the information menu, a 2 or 3 digit code will be displayed
representing each entry in the information menu. The first code
displayed will be t1. With each sequential press and release of
the SET key, the following codes will appear in this order: t1, thi,
tLo, Ahi, ALo, AdL, cnd, and Loc.
To view the value of each code, press and hold the SET key after
the desired code is displayed. Additionally, the WARMER and
COLDER keys may be used to scroll through the menu. To exit
the information menu, press the ON/OFF key, or wait for several
seconds with no key presses.
1) Current Interior Temperature (tI): While tl is
shown on the screen press and hold the “SET”
key to display the current interior temperature.
2) Maximum Stored Temperature (thi): While
thi is shown on the screen, press and hold the
“SET” key to display the maximum recorded
temperature. The temperature is updated every 5 minutes. To
reset the maximum temperature; continue to hold the SET key,
then press and release the ON/OFF key to reset the maximum
temperature. The maximum temperature will be reset to the
current compartment temperature.
It is recommended that thi be reset after the initial pull-down
(24 hours after power on) to clear any residual values.
3) Minimum Stored Temperature (tLO): While tLo
is shown on the screen, press and hold the “SET”
key to display the minimum recorded tempera-
ture. The temperature is updated every 5 minutes. Continue to
hold the SET key then, press and release the ON/OFF key to reset
the minimum temperature. The minimum temperature will
be reset to the current compartment temperature. It is recom-
mended that tLo be reset after the initial pull down (24 hours
after power on) to clear any residual values.
4) Relative High Temperature Alarm (Ahi): The
number of degrees C warmer relative to the
set temperature that will initiate a high tem-
perature alarm. Once the compartment temperature exceeds
the high temperature alarm value, the control will delay AdL
minutes before initiating the alarm. See Alarm Delay section
below for instructions to set alarm delay. While Ahi is displayed
on the screen, press and hold SET key to view the value of Ahi.
To adjust the value, continue to hold SET then use the WARMER
and COLDER keys until the desired value is shown on the screen.
Release the SET key to confirm the new setting. Factory default
value for Ahi is 2.0°C.
Note: Setting Ahi = 0 will disable the high temperature alarm.
The control’s 2°C Hysteresis value is automatically added to Ahi.
For example, let set temperature = 4°C, and Ahi = 3. The high
19