AAON RK-60 - Manual (Page 10)

10
INSTALLATION continued
Gas piping information is typical for one gas valve. For
units with dual heat exchangers, duplicate gas piping to
number two gas valve.
CONDENSATE PIPING
The RK equipment is furnished with drain connections
and 'P' traps are furnished with the equipment in the
same quantity as the drain connections. On the 'A', 'B'
and 'C' cabinet models (2 - 25 ton) require one drain
connection. On the 'D' cabinet models (26 - 60 ton) all 3
of the drain connections must be used and individually
trapped to ensure a minimum amount of condensate will
be present in the drain pans.
Drainage of condensate directly onto the roof may be
acceptable in certain areas, refer to applicable codes. If
condensate is to drain directly onto the roof, a small drip
pad should be placed below the drain to protect the roof
from possible damage.
When condensate is piped into the building drainage
system, the drain pipe should penetrate the roof exter-
nal to the unit itself. The drain line should be pitched
away from the unit at least 1/8 inch per foot. On longer
runs, an air break should be used to ensure proper
drainage.
Drain pans in any air conditioning equipment, even
when they have a built-in slope to the drain, will have
moisture present and will require periodic cleaning to
prevent any build up of algae of bacteria. Cleaning of the
drain pans will also prevent any possible plugging of the
drain lines and an overflow of the pan itself. All cleaning
of the drain pans and inside of the equipment should be
done by qualified personnel.
Typical 'P' trap
connection
FOR PROPER UNIT OPERATION,
DRAIN TRAP MUST BE INSTALLED AS SHOWN.
USE ABS TYPE CEMENT TO JOIN THE CONNECTIONS.
In compliance with the ANSI Standard, installations
exceeding 2-psi or less than 5-psi nominal require a
tested and approved over-pressure protection device for
use with the regulator.
For proper heater operation, pressure to the regulator
MUST NOT BE greater than 5-psi.
Nominal
Iron Pipe
Size, Inches 10 50 100 200
GAS PIPING CAPACITIES
3/4" 278 115 79 55
1" 520 215 150 100
1 1/4" 1050 440 305 210
1 1/2" 1600 670 460 320
2 3050 1270 870 610
2 1/2" 4800 2000 1400 980
LENGTH OF PIPE, FEET
Max. Capacity of Gas Pipe in Cubic Ft. Per Hour*
*At gas pressure of 0.5 PSIG or less and a pressure
drop of 0.5 inches of water. Specific gravity = 0.60.
Utility
Access
Gas
Shut-off
Valve*
Heat
Exchanger
Gas
Valve
Union*
GAS PIPING ILLUSTRATION
*Gas piping field installed by others
GAS PRESSURE REGULATOR & OVER-PRESSURE
PROTECTION DEVICE
On applications where gas service to the unit is greater
than 10.5"w.c. and less than 2-psi, a gas pressure regu-
lator must be installed.
At supply pressures in excess of 2-psi and less than 5-
psi, ANSI Z21.80 line regulator standard requires a
means (an over-pressure protection device / OPD) to
limit the downstream pressure to 2-psi maximum, in the
event of regulator failure.
Optional
Gas Pressure Regulator
2 to 25 ton Models Require (1) Connection.
26 to 60 ton Models Require (3) Connections.