York YLAA Operation Manual page 17

Accessories and Options (Cont'd)
JOHNSON CONTROLS
COMPRESSOR, PIPING, EVAPORATOR OPTIONS:
Low Temperature Glycol – Replaces standard Thermostatic Expansion Valves with Elec-
tronic Expansion Valves to achieve leaving glycol temperatures as low as 10°F (-12°C). Re-
quired for any leaving liquid temperature below 30°F (-1°C). Electronic Expansion Valves
permit operation at both low temperatures and comfort cooling applications without a capac-
ity loss or derate at either condition.
Chicago Code Relief Valves – Unit will be provided with relief valves to meet Chicago
code requirements.
Service Suction Isolation Valve – Service suction discharge (ball-type) isolation valves
are added to unit per system (discharge service ball-type isolation valve is standard on each
circuit).
Hot Gas By-Pass – Permits continuous, stable operation at capacities below the minimum
step of compressor unloading to as low as 5% capacity (depending on both the unit and
operating conditions) by introducing an artificial load on the evaporator. Hot gas by-pass is
installed on only refrigerant system #1.
Thermal Dispersion Flow Switch – A thermal dispersion type flow switch provides accu-
rate, low maintenance flow proving and is included standard. It is factory wired and installed
in the extension pipe between evaporator outlet and edge of chiller. The extension pipe is
secured to the chiller frame for shipping to avoid risk of damage to evaporator and is easily
attached to the evaporator at startup using the supplied ANSI/AWWA C-606 connector. The
flow switch can be deleted if alternate or existing flow switch is field supplied.
Evaporator Nozzle Extension Kit – Pipe and ANSI/AWWA C-606 fittings to extend the
evaporator connections to the outside of the chiller. Includes the Thermal Dispersion Flow
Switch. Provided as standard on all chillers but can be deleted if alternate or existing pip-
ing and flow switch is field supplied. The extension pipe is secured to the chiller frame for
shipping to avoid risk of damage to evaporator and is easily attached to the evaporator at
startup using the supplied ANSI/AWWA C-606 connector. A support bracket for the exten-
sion kit or field piping is standard on all chillers. Extension kit insulation and heat trace to be
field provided if required.
Heat Recovery Condenser – A partially condensing refrigerant to liquid condenser recov-
ers heat off both refrigerant circuits and rejects into a single liquid circuit. Factory installed
between the compressor discharge and the condenser (air) coils to capture the maximum
amount of heat. Capable of recovering up to 85% total heat of rejection (cooling load plus
work input); temperatures as high as 140°F (60°C) are possible.
Hydro-Kit – Factory installed Hydro-Kit suitable for water glycol systems with up to 35%
glycol at leaving temperatures down to 20°F (-6.7°C). The hydro-kit option is available in a
single or dual configuration (dual as standby duty only), with totally enclosed permanently
lubricated pump motors.
The hydro-kit comes standard with a variable speed drive, a balancing valve, discharge
check valve, discharge shutoff valve, thermal dispersion flow switch, pressure ports, inlet
wye-strainer, bleed and drain valves and frost protection.
Service shut off valves, additional pressure ports and taps for the expansion tank are op-
tional within the hydro-kit option. Expansion tanks are available by request.
FORM 150.72-EG6 (516)
17