Heatcraft Refrigeration Products BEACON II H-IM-79E, Installation And Operation Manual

17

Defrost Delay Start Time 

Example: The system is first powered up at 8:00 AM and 
is programmed for 4 defrost per day. The user would like 
the first defrost at 10:00 AM. To accomplish this, use the 

“PROGRAM REVIEW”

 button to scroll to 

dFS

. Use the 

“SELECTOR” switch to select 2 hours delay start, then 
press 

“ENTER.”

 The 1

st

 defrost will now occur at 10:00 

AM and then a defrost will occur every 6 hours thereafter.

Time Remaining Until Next Defrost

(On Version 1.8 Boards) 

To find out how much time is left until the next defrost is 
scheduled, use the 

“MONITOR”

 button to scroll to 

dFS

. 

The time displayed will be how much time until the next 
scheduled defrost.

Defrost Schedule In Memory 

Beacon II does not have a real time clock but it keeps 
track of the time that has elapsed in its memory. It also 
keeps in memory the number of defrosts scheduled 
and how much time has elapsed between defrosts. If a 
power failure occurs, when power is restored Beacon 
II remembers how many defrosts are scheduled and 
it remembers how much time was left until the next 
defrost. It will then defrost based on this timing. So, if the 
power failure lasted 15 minutes, the defrost schedule will 
be off by 15 minutes.

Resetting Defrost Schedule 

When a power interruption causes a severe lag in the 
defrost schedule, the defrost schedule can be reset in 
the following manner. First, press the reset time button 
on the board to zero out the internal counters. Then, 
program the appropriate defrost delay start time for the 
next desired defrost period. The defrost schedule will be 
correct until you have another power outage.

Pumpdown / Defrost

Service Mode 

A single pole, single throw switch (SPST) is supplied in 
each condensing unit for shutting off the system. Closing 
the “

SERVICE

” switch in the condensing unit will cause 

the system to pumpdown and shut off. “

Ser

” will be 

displayed on the Beacon board LED and “

SERVIC

” 

is displayed on the Smart Controller LCD display. The 
evaporator fan and heaters will be de-energized in the 
Service Mode.  

The system will not restart until the SPST switch is 

placed in the “NORMAL” or “OFF” position.

OR

A remote “

SERVICE

” switch can be added to the 

Beacon II board across the “

Ser

” and “

C

” connections of 

the terminal block. It will operate in the same manner as 
the switch above.

OR

The system can be pumped down by pressing the 

“SERVICE”

 button twice. To restart the system, press 

the 

“CLEAR”

 button.

OR

The system can be pumpdown for service by closing 
the liquid line service valve in the condensing unit, then 
closing the suction line service valve when the system 
trips on the low pressure switch.

In order for air defrost evaporator fan motors to cycle off 
during “

SERVICE

” mode, the fan motors must be wired 

through the fan relay on the Beacon II board.

Defrost

Defrost Timing 

When power is first applied to the system, its timer 
starts counting time. If 4 defrost are programmed, it will 
initiate a defrost every 6 hours from when power was 
first applied. Beacon II does not have a real time clock. 
Beacon II does provide the ability to delay the starting of 
the first defrost.