Case Connections - Barker PTD-RGC Installation & Operation Manual

Multi-deck merchandiser deli/meat/seafood

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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 even 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-

tive "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 indicates 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 requires "bumping the pump".

The pump is capable of emptying the reservoir 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 above "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.

▲

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.

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