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Pegasus High Temperature Controller Shortform 

ZA0937-ZBC Issue E  

 

May18, 2007. 

Honeywell Refrigeration Control, Newhouse Industrial Estate, Motherwell, ML1 5SB. 
Tel: 01698 481698, Fax: 01698 481699, Web: 

www.refrigeration.europe.honeywell.com

 

Overview 

Pegasus (Figure 2) is a refrigeration controller 
used to switch refrigeration ON, if  the operating 
temperature (4

o

C) exceeds the running 

temperature setting, and OFF  if the  operating 
temperature falls below the running temperature 
setting by 3

o

C. Four bit switches  located on the 

controller board control the frequency defrost.  A 
display (Figure 1), connected to the controller can 
show either the operating temperature or one of 
the following four messages: 

1. 

dF: the controller is in defrost

 

2. 

Flashing between dF and operating 
temperature: controller  is recovering  from 
defrost

 

3. 

Flashing between PF1 and 30

o

C: probe failure

 

4. 

Flashing between AL and operating 
temperature: over temperature alarm

 

The maximum defrost time is set  by adjusting 
RV4 and viewed whilst in the setting mode. Table 
1 below, describes these settings: 

Channel 
ID 

Reading 

Pot 

Range  

Pr 

Case 
temperature 
probe 

 

-30

o

C to 

+30

o

Ch4 

Maximum 
defrost 
time 

RV4 

10 to 40 
minutes 

Table 1: Pegasus Control Settings 

Defrost Settings 

The controller initiates defrosts at intervals set on 
the defrost frequency switches (Table  2). 

The compressor is held OFF for the maximum 
defrost period, during defrost. 

After defrost the controller enters the recovery 
state. The compressor is cycled as normal for 15 
minutes. During recovery the display flashes 
between the operating temperature and “dF”. 

Setting Mode 

Setting mode is selected using the channel setting 
push button (or an optional remote channel select 
button) on the controller board. Hold down the 
button to view the termination time (Ch4) on the 
display (Table 1). Release the button to see the 
value appropriate to that channel. Adjust  the 
setting using a screwdriver whilst the appropriate 

channel is selected. The display automatically 
reverts to normal after a period of 30 seconds. 

Probes 

Pegasus  is equipped with two inputs; P1 and 
AUX. The case temperature probe connects to P1 
and the manual defrost initiation switch to AUX. 

Power Up 

The fans are powered continuously from a supply 
on the board. The compressor is held OFF for two 
minutes after power up. 

Hold down the channel  select button whilst the 
case is switched on to override the two minute 
delay period and start the compressor immediately 
on power up. 

Case Test Mode 

Put the controller into test mode by connecting the 
link on LK2 (Figure 2). Bit switch 3 now controls 
the relay output. The display shows bC followed 
by the software version. 

Over Temperature Alarm 

The over temperature alarm  level is set at  10

o

with a 30 minute alarm delay. The over 
temperature alarm level and the alarm delay 
cannot be altered. The over temperature alarm is 
disabled during defrost. 

Compressor Minimum On/Off Time 

The minimum ON/OFF time ensures that when 
the compressor  switches ON/OFF, it remains 
ON/OFF, for a minimum period of two minutes. 

Probe Fault 

If a probe fault occurs on P1, the display flashes 
between PF1 and  30

o

C. The compressor switches 

ON and then OFF continuously , every 8 minutes. 

Connecting a Display 

Connect the display to your Pegasus controller 
using the inf ormation shown in Figures 1 and 2.  

 

Figure 1: Connecting a Display 

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