9
Remote Condensing Unit Installation Instructions
©2019 Tecumseh Compressor Company LLC. All rights reserved.
TPC Part #71511 | Rev A 05/13/2019
www.tecumseh.com
HEAD PRESSURE SYSTEMS
If you are charging the system by using a clear sight glass as an indication of proper charge (210 psi for R404A
units and 180 psi for R22 units) the following must be considered.
Check the condensing temperature. It must be above 92°F. If not, it will be necessary to reduce the amount of air
going through the condenser from fans still running. Simply reduce the effective condenser face area to raise the
discharge pressure above the equivalent 92°F condensing temperature and then proceed to charge to clear the
sight glass. Adjust evaporator superheat. Return to full condenser face area and allow the system to balance.
HEAD PRESSURE CONTROLS
The standard valve used on high pressure refrigerant systems controls the head
pressure. There is no adjustment for this valve.
At condensing pressures above the valve setting, flow enters Port C and leaves
Port R. When the condensing pressure falls below the valve setting, the valve
modulates to permit discharge gas to enter Port D. Metering discharge gas into the
refrigerant flow leaving the condenser produces a higher pressure at the condenser
outlet, reduces the flow, and causes the level of liquid refrigerant to rise in the
condenser. This “flooding” of the condenser with liquid refrigerant reduces
the available condensing surface, holding the condensing pressure at the valve
setting.
(See Figure 5)
REFRIGERANT FLOODING CHARGE
The Refrigerant Flooding Charge Tables (appendix) summarize the coil charges for ARGUS Outdoor Condensing Units.
Winter charge assumes 90% flooded coil; Summer charge assumes 10% flooded coil.
These charges are approximate and should not be used as absolute rules for charging the system.
To determine total system charge, the liquid line and unit cooler must be considered.
Condenser
Receiver
Compressor
D
R
C
Head Pressure
Control Valve
Figure 5
Single Valve Flooding Piping Arrangement
Approved Hermetic Compressor Oils
Hermetic compressors are charged with optimum oil that will be adequate for systems designed in accordance
with good engineering practice.
For questions call Technical Support.
Refrigerant
Approved Compressor Oils
R-404A, R-407A,
R-448A, R-452A,
and R-449A
Polyol Ester (with approved additives)
AE2, AK2, AKA, AJA, AWG,
AVA, AGA,VSC, VSCF
Witco-Suniso SL32, SL22; Penreco Sontex SEZ32 SEZ-22; Castrol Inc. Icematic SW-32;
Mobil EAL Arctic 32, 22; Emery 2927-A; ICI Emkarate RL32S
Some system designs containing unusual evaporators or extensive interconnecting pipes, may require additional oil.
Since excess oil can also damage compressors, care should be taken not to exceed the oil charge amounts specified.
REFRIGERATION OILS
Summary of Contents for Argus
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