Barker GMD-R, Installation & Operation Manual

SEMI-SELF-CONTAINED

Hillphoenix SSC (Semi-Self-Contained) cases utilize an open-
loop secondary system, supplying independent circuits to the 
Coolgenix pans, shelves and the gravity top coils.  All circuits 
return to a common reservoir tank that is maintained at atmo-
spheric pressure.  All cases are tested and shipped with a 35% 
mixture of Dowfrost propyleneglycol.

Charging the refrigeration system is imperative to maximizing 
case performance by ensuring that excess air is eliminated 
from the system - excessive air in the system can reduce 
the heat transfer capacity and e

ven block the fl ow to one or 

more of the heat transfer components (e.g. Coolgenix Pans or 
section of the top coils).  Also, charging the system fl oods the 
pump, which helps prevent damage caused by cavitation.  

Starting a Newly Delivered SSC Case

Unless otherwise specifi ed, all SSC cases are charged and 

tested at the factory.  Much of the fl uid is drained out of the 
reservoir to prevent spillage during shipment and handling.  
Before starting the case, the DX (direct expansion) side of the 
chiller must be connected to the appropriate refrigerant lines 
and the power connected to the case.  

Starting the case consists of topping-off the reservoir tank and 
ensuring that all hand-valves are open, then supplying power 
by turning the main control and pump switches to their respec-
tiv

e "ON" positions.  This requires access to the chiller and the 

electrical box.  

For cases with pedestals, the chiller is located in the right-
hand pedestal while the electrical box is in the left-hand ped-
estal.  The fi lling tube can be accessed by removing only the 
rear of the right hand pedestal.  Cases that are fully skirted 
require the removal of the lower back panel to access the 
chiller and the electrical box.  

There are 2 indicator lamps - one red, one blue - located in 
the upper back panel.  The red lamp indicat

es that the fl uid 

level in the reservoir is low and should be topped-off.  The blue 
lamp indicates that the reservoir is full and that no more glycol 
should be added to avoid spills.  If neither lamp is lit, the fl uid 
level is in the operating range.  To top-off the reservoir, remove 

the fi lling tube from its holding position and extend it to insure 
that there are no kinks or obstructions.  Remove the charging 
cap and pour in propyleneglycol (use only 35% Dowfrost) until 
the blue lamp lights, indicating that the reservoir tank is full.  
Replace the charging cap and return the hose to its holding 
position.

Recharging a Drained System

There may be circumstances when the glycol system needs to 

be drained, fl ushed, and recharged - usually due to contami-
nants being added to the approved propylene glycol.  Charging 

and air purging should be performed with the hand-valve on 
the DX-side of the chiller closed.  

Field charging the chiller system req

uires "bumping the pump".  

The pump is capable of emptying the reser

voir faster than fl uid 

can be poured into it.  When the system is empty, the reservoir 

must be fi lled until the blue light is illuminated.  The pump 
should then be "bumped" on-and-off using the pump switch 
until the red light comes on.  The reservoir has to be refi lled 
and the process repeated until the red light no longer comes 
on.  The pump can then be left on.  

Each circuit in the system may be cycled by adjusting the set-
point values abo

ve "AMBIENT" to stop fl ow and below "FLUID 

TEMPERATURE" to force fl ow.  This will help force any en-
trapped air out of the pans and top coils.  The fl ow through the 
system is never perfectly silent; however if an obvious gurgling 
sound is heard in any of the pans or at the outlet of a top coil, 
this indicates air movement at that location.  

Increased fl ow can be forced by restricting the fl ow to the other 
components in the circuit.  For pans with quick connects, this 
can be done by disconnecting one of the hoses to the non-
problem pans.  For pans without quick connects, the fl ow can 
be restricted by pinching the feed hoses on the non-problem 
components.  Do not use any kind of clamp that could cut or 
tear the hoses.  

There are also Schrader fi ttings in the return headers of each 
of the top coils.  Entrapped air may be bled off by depressing 
the core of the fi tting or removing it until a solid fl uid stream 
is present.  While purging air, be certain to make note of the 
red indicator lamp - do not allow the reservoir to empty.  Once 
the majority of the air is purged and the case is performing 
acceptably, top-off the reservoir until the blue lamp is on, open 
the DX-side hand valve, and close up the case.  Any incidental 
air in the system will be removed during the normal operation 
of the case.

C A U T I O N

Dowfrost propylene glycol is used for pres-
sure testing and system charging.  If another 
approved glycol is utilized, the case MUST be 
fl ushed with pure water to remove any residual 
glycol before fi lling.  Failure to do so will void the 
manufacturer warrarnty.  Never mix manufactur-
ers of glycol. 

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CASE CONNECTIONS

REFRIGERATION

Refrigeration connections will be made through the refrigera-
tion stub up location on the customer left side of the case.   
Refrigeration lines may be headed together for all cases in a 
line-up, if necessary, by lines through the access holes with a 
high grade silicon to prevent recirculation.  All lines must be 

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