Leslie Controls NYC Heat Exchanger - Manual (Page 10)

Page 10 of 25
Second switch = 130 degrees F
Should an over temperature condition occur a temperature
switch in first or second stage of one or both sides of the
unit will recognize this and switch the relay in the control
box. Relay will:
1. Cause solenoid supplying hot water to shut off
supply of hot water to output of system.
2. Cause three way valve (101) to rotate and divert
condensate water away from condensate cooler
and send it directly to drain.
3. Cause “RESET”, “NO. 1 HEATER OVER
TEMPERATURE “NO. 2 HEATER OVER
TEMPERATURE” light or all three lights to light
up.
4. When temperature switch senses the water
temperature has cooled down and the three way
valve has reached its full rotation, relay in the
control box will switch three way valve to rotate
back to its original position. Only then will the
solenoid valves open up again and normal
operation begin.
H. GENERAL SETUP AND
OPERATION OF BLEND VALVE
INITIAL SETTING OF GAIN ADJUSTER VALVES
PROCEDURE
1. Ensure all connections are made and unit is
running at specified maximum flow.
2. Turn off supply of water to one side. Half of
specified maximum flow is now being delivered.
3. Check outlet water temperature and insure it is
120 degrees F.
4. If warmer then turn gain valve handle
counterclockwise for ¼ turn.
5. Recheck water temperature and repeat until
reaching desired temperature.
6. Note: Temperature will not change quickly and
must be left to seek it’s normal setting.
7. If the water was colder then turn the gain valve
handle clockwise for ¼ turn.
8. Recheck water temperature and repeat until
reaching desired temperature.
9. Re-open the supply of water to side turned off.
Wait for the system to stabilize.
10. Repeat step 2 through 9 for the second side.
BLEND VALVE OPERATION
Motive force of operation comes from expansion of a
special wax material which remains in a semi-solid form
and which is highly sensitive to temperature changes.
Upon warming sliding valve moves up to extended
position. By-pass closes off as sliding valve seats and
water is diverted to outlet (Port C on valve). In actual
operation, sliding valve is normally in about mid-position.
When wax material expands with rising temperature,
rubber plug is forced into a reduced diameter in piston
guide, which multiplies movement of piston by and
extruding action.
Operating range is determined by chemical composition
of wax material. Expanding wax develops a pressure that
easily overcomes return spring force of over 100 lb.
Construction is simple and rugged, yet unit is very
sensitive to changes in temperature. Changes in pressure
do not affect element and, due to valve construction,
surges in pressure do not tend to upset stability of
Thermostatic valve.
Thermostatic valves have Tamper-Proof Temperature
Setting, and are Completely Self-Contained.
3-way action of thermostatic valve allows a constant
volume of water through system at all times with no
restriction to flow when system is cold.
MATERIALS OF CONSTRUCTION
Temperature Element Assemblies are made of brass and
bronze. Seals are Buna N. Certain fluids may be damaging
to standard valve body and seal materials.
TEMPERATURE SETTINGS
Thermostatic Valves are set to a predetermined
temperature at factory, errors due to mistakes of operating
personnel are eliminated. After a Thermostatic Valve had
been installed, it is impossible for operator to arbitrarily
change operating temperature unless element assemblies
themselves are changed.
For long life, Thermostatic Valves should not be operated
continuously at temperatures more than about 25ºF (14ºC)
above their nominal ratings. If higher continuous over
temperatures
are expected, contact factory for
recommendations.
NOTE
Gain adjuster valves, item 39 are used to adjust cold
water to final blend valve to insure holding set
temperature over flow range of unit. Valves are
generally set at 4.5 turns from full open position,
however they should be adjusted for each installation
since each building has it’s own characteristics.
Valves should be re-adjusted when season
changes from winter to summer.