Bryant 451A - Manual (Page 8)

larger than 20 gallon capacity, add one-half (1/2)
package for each additional 10 gallon capacity or
fraction thereof. (Consult Bryant distributor for
estimating chilled water circuit capacities.)
11. The system is now ready to operate.
Note: The condenser fan belt is factory set and
is self-adjusting. No field adjustment is necessary.
VI. CHECK OUT AND OPERATION
1. Be sure main manual gas valve is off. Light
pilot as described on instruction plate.
2. Set thermostat to “cool”; set thermostat fan
switch to “auto”; set thermostat below room
temperature.
3. Turn on main electric switch to unit.
4. Check indoor fan operation by turning thermo­
stat fan switch to “on” for continuous fan opera­
tion. Move thermostat above room temperature and
observe that the indoor fan remains on.
5. To place the system in operation, open the main
manual gas valve, replace all panels, and set the
thermostat at the desired temperature.
High Temperature Cut-Off
The high temperature circuit includes a high tem­
perature control located on the front of the gen­
erator plus a high temperature relay (lockout
relay) located in the control box. If the generator
becomes overheated the contacts in the high temp
control open, causing the high temp relay to go
into lockout position. The gas valve closes, the
fans and pump stop, and they will not recycle until
the lockout relay is reset. To reset lockout relay
turn electric power off and then back on.
Be sure
to locate and correct cause of high temp cut-out.
VII. ADJUST GAS INPUT
Gas input should agree with that shown on the
rating plate of the unit. The burners are equipped
with fixed orifices intended to give the correct
gas input with a manifold pressure of 3" w.c.,
using 1030 BTU natural gas of 0.63 S.G. Before
lighting burners, inspect to be sure that they have
not become dislodged or cocked during shipment
and installation.
To measure gas input, proceed as follows:
1. Adjust primary air if necessary.
2. Measure the gas input at the meter. Be sure all
other gas appliances are turned off. Input at the
burners may be increased or decreased slightly
by adjustment of the regulator in the burner supply
line.
Caution: Prolonged operation of the unit should
not be attempted with the panel off. The unit
may be run for short periods with the panel re­
moved.
VIII. BALANCE THE SYSTEM
After the unit is in operation and the input has
been measured and adjusted to agree with the
rating plate requirements, balance the system.
Any approved method of checking the air flow over
the water coil may be utilized. Reference is made
to the Bryant Service Manual on Gas Air Condi­
tioners for a review of standard methods.
IX. PURGE NON-CONDENSIBLES
Purging is accomplished through valve A on inlet
tank and Valve
D on purge pot.
Operate unit for a minimum of 15 minutes. While
still operating, proceed as follows:
1. Attach adapter and purge line to Valve A.
2. Run purge line to bucket of water.
3. Remove cap and open valve A about 1/8 to 1/4
turn.
4. If non-condensibles are present, bubbles will
rise to the surface of the water in the bucket.
5. Leave Valve A open as long as bubbles rise
to the surface of the water. When non-condensibles
are removed the bubbles will cease as ammonia
will be absorbed into the water.
6. Close Valve A.
7. Open Valve D about 1/8 turn. Usually there
will be some solution trapped in the valve body,
and this solution will be released as soon as the
valve is opened.
EH 451 - 6