York H2CA600 - User Manual

GENERAL
A Hot Gas Bypass valve is a fully modulating control that will
provide a metered flow of compressor discharge gas to the
system’s evaporator coil during reduced load operation to
prevent condensate from freezing on the surface of the evapo-
rator coil.
Hot Gas Bypass may be required when a CA condensing unit
is applied on:
1. A multi-zone (MZ) system,
2. A throttling-type variable air volume (VAV) system,
3. A system handling 100% outdoor air, or
4. Any system where condensate may freeze on the surface
of the evaporator coil during low load operation.
NOTE: The need for hot gas bypass can be reduced or
eliminated on some systems by splitting the coils
for row control instead of face control.
When hot gas bypass is required, York recommends that:
1. One end of the main bypass line be connected to the inlet
of the evaporator coil between the expansion valve and the
distributor of the system’s first stage of capacity. This ar-
rangement is required to maintain a high gas velocity and
good oil return through both the coil and the suction riser
during hot gas operation.
2. The other end of the main bypass line be connected to the
7/8" spud that is provided in the compressor discharge
header of the condenser coil. On units with two independent
systems (models CA480 and 600), the bypass line should
always be connected to the #1 system. Although the #2
system will also have a 7/8" spud connection, a second hot
gas bypass line should not be required unless systems 1
and 2 are applied with different evaporator units.
3. A pilot-operated valve (an Alco FA8-13H or equal) be used.
This valve includes a 24-volt solenoid which closes the
bypass line and permits the system to shut down after the
normal pumpdown cycle. See Figure 1.
NOTE: To use the recommended valve, the overall system
control circuit and the evaporator coil must have as
many capacity stages as the CA unit and each
stage of the evaporator coil must be equipped with
both an expansion valve and a solenoid valve. If a
system is not designed to unload to its minimum
capacity, a larger hot gas bypass valve may be
required.
4. A 1/4" pilot line be connected between the access port on
the hot gas bypass valve and one of the suction access
ports on the compressor. Use either the one labeled A or B
on Figure 2. The access port labeled C will already be
connected to the system’s low pressure control.
NOTE: When using port A, make the connection before the
system is charged because refrigerant will be lost
whenever this access port is opened. Although the
suction stop valve can be backseated to close port
B, port B may be needed for a suction pressure
control and/or a service connection.
AIR COOLED
SPLIT-SYSTEM AIR CONDITIONERS
INSTALLATION INSTRUCTION
Supersedes: 550.12-N6 (579)
550.13-N6Y (399)
HOT GAS BYPASS
MODELS H2CA600
®
FIG. 1
- ALCO PILOT-OPERATED VALVE - FA8-13H

Summary

General Hot Gas Bypass Information

Evaporator Coil Bypass Connection

Connect one end of the bypass line to the evaporator coil inlet between the expansion valve and distributor.

Compressor Discharge Header Connection

Connect the other end to the 7/8" spud on the compressor discharge header; use system #1 for twin systems.

Recommended Pilot-Operated Valve

Use a pilot-operated valve, like Alco FA8-13H, with a 24-volt solenoid for proper operation.

Pilot Line Connection to Suction Port

Connect a 1/4" pilot line from the bypass valve access port to a compressor suction access port.

Hot Gas Bypass Installation Procedure

Release System Refrigerant

Open access ports on liquid and suction stop valves to release system refrigerant.

Prepare Discharge Header Spud

Prepare the 7/8" spud connection on the compressor discharge header using a tube cutter.

Secure Support Bracket

Securely attach the support bracket for the hot gas valve to the compressor compartment base.

Mount Hot Gas Bypass Valve

Mount the hot gas bypass valve to the fabricated "U"-shaped support bracket.

Connect Nitrogen for Brazing

Connect dry nitrogen to the liquid line stop valve access port for brazing.

Braze Bypass Lines

Braze the lines connecting the discharge header to the valve inlet and valve outlet to the evaporator coil.

Connect Pilot Line to Suction Port

Connect a 1/4" flare line from the valve access port to the compressor suction access port.

Connect Solenoid Wiring

Wire the hot gas valve solenoid between terminals C1 and T on the CA unit's 24-volt terminal block.

Insulate Bypass Line

Ensure the entire hot gas bypass line is properly insulated after installation.

York H2CA600 Specifications

General

Brand	York
Model	H2CA600
Category	Air Conditioner
Language	English