Heatcraft Mohave Installation & Operation Manual Download Page 51

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Program Review

Note: all items listed below are only viewable when the Expert Mode option is turned on.

Condenser Fan #x Operation Method –

FANX

– Note that x represents a value between

1 and 4, and is selected in descending order following #1. Selection is made for type of fan
operation control. Choices are: OFF, ON, PRES, and AMBT. The selection made will determine
the parameter type of the operation ranges. Default: PRES.

Condenser Fan #x ON operation value –

FXON

– Note that x represents a value between

1 and 4, and is selected in descending order following #1. This setting chooses the on value
for the fan selected. When ON or OFF is chosen for a particular fan operation, this step will
not be displayed. If

AMBT

was chosen, the value displayed is a temperature in °F. The

temperature selection range is 30°F to 90°F. If

PRES

was selected, the value displayed

represents a pressure in ‘psig’. The pressure selection range is 110 psig to 300 psig.

Condenser Fan #x OFF operation value – FxOF – Note that x represents a value between 1
and 4, and is selected in descending order following #1. This setting chooses the off value
for the fan selected. When ON or OFF is chosen for a particular fan operation, this step will
not be displayed. If

AMBT

was chosen, the value displayed is a temperature in °F. The

temperature selection range is 30°F to 90°F. If

PRES

was selected, the value displayed

represents a pressure in ‘psig’. The pressure selection range is 110 psig to 300 psig.

Defrost Termination Temp for Evaporator #1 –

DFT1

– This is the temperature as sensed

from the evaporator suction line that is used to determine when the defrost cycle is complete.
The value is displayed as a temperature.
Default: 75°F (Low Temperature) 85°F (Medium Temperature)

Defrost Termination Temp for Evaporator #2 –

DFT2

– This is the temperature as sensed

from the evaporator suction line that is used to determine when the defrost cycle is complete.
The value is displayed as a temperature. Note: when two evaporators are used, both evaporator
temperatures must reach their set point to terminate defrost. Default: Same as

DFT1

Defrost Termination Pressure –

DEFP

– Selection is made of the pressure value that

will signify a complete defrost process. This decision is made in an ‘OR’ manner with the
defrost termination temperature and the defrost failsafe time. That is, if any one of the defrost
termination parameters is satisfied, the defrost will terminate. The value displayed is a pressure
in ‘psig’ format. Default: 210 PSIG.

Defrost Failsafe Time –

DEFT

– This is the maximum time allowed for a coil to remain in

defrost. Defrost will be terminated if the defrost end temperature measured at the evaporator(s)
(both must be at temp if two evaporators) or the defrost end pressure is not attained when this
time has expired. Default: 25 minutes.

Equalizing Time –

EQUT

– This is the duration time of the ‘pre-defrost’ pressure

equalization process and the ‘post-defrost’ drain time. The selection range is 1 minute to 10
minutes. Default: 2 minutes.

Evaporator Refreeze Temperature –

FZET

– This is the evaporator temperature at which

the fans energize after the refreeze (fan delay) period unless the maximum refreeze time is
reached. The selection range is 20F to 40F.

Evaporator Refreeze Maximum Time -

FZTM

- This is the maximum time for the refreeze

(fan delay) period. The selection range is 0 to 10 minutes.

Note:

*Available on Software version V1.04 and higher

**Available on Software version V1.06 and higher

***Menu Re-Ordered on Software version V2.05 and higher

Low Pressure Switch simulation ‘Cut-In’ value –

LPSH

– Selection is made of the ‘cut-in’

pressure value normally made on the mechanical low-pressure control switch. The value
displayed is a pressure in ‘psig’ format.
The pressure range is 0 psig to 30 psig.

Low Pressure Switch simulation Cut-Out value –

LPSL

– Selection is made of the ‘cut-

out’ pressure value normally made on the mechanical low-pressure control switch. The value
displayed is a pressure in ‘psig’ format. The pressure range is 0 psig to 30 psig.
Electronic Pressure Regulator Manufacturer

VALM

- This parameter controls the Electronic

Pressure Regulator Settings that are loaded for each corresponding application to match the
installed valve (Carel or Alco). Default: Carel (CARL).

Electronic Pressure Regulator -

PRFS, PRUI, DFIO

- These parameters

control the operation of the pressure regulator during the defrost period and the default
selections are tuned to specific condensing unit models. Field modification is not recommended.
Default: See table of factory default settings.

Liquid solenoid pulse feature -

LLSP

- In the period immediately after defrost, the

evaporator fans will energize and the liquid solenoid valve may be pulsed to reduce the
evaporating temperature and give the warm thermostatic expansion valve additional time to
close. This feature will function primarily on medium temperature systems and is adjustable from
0 to 15 minutes. Default: 5 minutes.

Evaporator fan run operation

EVPF

- This parameter controls the status of the evaporator

fans during the refrigeration off-cycle when the thermostat is satisfied. (On or OFF) Default: On.

High auxiliary temperature alarm –

ALHR

– This parameter is the temperature set point that

when measured above by the auxiliary temperature sensor will cause an ALR5 alarm after the
alarm time has been exceeded. Default: OFF.

Low auxiliary temperature alarm –

ALRL

– This parameter is the temperature set point that

when measured below by the auxiliary temperature sensor will cause an ALR6 alarm after the
alarm time has been exceeded. Default: OFF.

Auxiliary temperature sensor thermostat control –

AUXT

– This parameter will allow the

auxiliary temperature sensor to be used as a box thermostat control. Auxiliary temperature
sensor can be extended up to 500ft using 18 gauge wire. There is no alarm provision for an
auxiliary sensor failure and an external box temperature alarm is recommended if this
functionality is desired. When used for box thermostat functionality setting the low and high
temperature alarms (parameters ALRL, ALRH) is recommended. The recommended location
of the auxiliary temperature sensor for box thermostat control is on the inlet air side of the
evaporator. Default: OFF.

Box thermostat set point –

BOXT

– This parameter is the box temperature, or room

temperature, set point that the Mohave board will control to using the auxiliary temperature
sensor if parameter AUXT is enabled. There is a non-changeable 1 degree differential around
this set point for refrigeration operation. This parameter will only appear in the menu if

AUXT

is enabled. Default 35 degrees Fahrenheit. The box thermostat set-point range is

-25°F

to 50°F.

Modbus address -

MBAd

- multiple Mohave control boards may be connected via Modbus

RS-485, which allows monitor menu functions and system status to be viewed. This setting
allows each board to be addressed uniquely (1 to 50). Default: 1. Consult Heatcraft application
engineering for further support.