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Status indicator led, Low ambient operation, Pumpdown – Heatcraft Refrigeration Products BEACON II H-IM-79E User Manual

Page 15: Periodic pumpdown

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15

STATUS INDICATOR LED

• ERRORS

E 1

- Room temperature sensor shorted, open or not installed

E 2

- Defrost temperature sensor shorted, open or not installed

E 3

- Suction temperature sensor shorted, open or not installed

E 4

- Suction pressure transducer shorted, open or not installed

E 5

- Outdoor temperature sensor shorted

E 6

- Low superheat during cooling

E 7

- Compressor shutdown

(high or low refrigerant pressure or low oil pressure)

E 9

- Multi-in/Multi-out wiring error

• OTHERS

Coo

- Room Temperature sensor open or not connected

(Instead of displaying box temperature)

Loc

- Board is locked. Settings cannot be changed

UnL

- Unlock the board settings

Low Ambient Operation

All units are shipped standard with head master valves.
(Scroll compressor units have a 100 PSI head master
valve and all other systems have a 180 PSI head master
valve.) Condensing units with

multiple condenser fans

will have one or more fans cycle on pressure fan cycling
switch.

An adjustable time delay relay, factory set at 1 minute,
is wired across the low pressure switch (LPS). In cold
ambient, this allows time for the suction pressure to build
up and prevent nuisance tripping of the LPS.

Pumpdown

At the end of each cooling cycle, when the box
temperature is met, the Beacon system will pump down
and shut off the compressor.

To pumpdown, the EEV closes and the compressor runs
until one of the following occurs:

The low pressure switch opens

The suction pressure at the evaporator

is 4 psig

A total of two minutes has elapsed

Status Indicator LED

When any of these three conditions occurs, the
compressor will turn off and not restart until there is a
call for cooling or a periodic pumpdown.

Periodic Pumpdown

While in the OFF cycle, if there isn’t a call for cooling
(Box setpoint temperature is met) but:

The evaporator suction pressure has

risen to 10 psig

The low pressure switch has closed

The system will initiate pumpdown. This periodic
pumpdown will occur at 4 minute intervals when these
two conditions are met.