Water Temperature Adjustment And Scalding; High Elevation Installations - NTI TRX II Series Installation Start-Up Maintenance

CAUTION
On TRX150 / TRX199 Models ONLY
If the boiler is to be used only in Heating Mode (not connected to an
indirect water heater), the electrical connection of the 3-way valve
motor MUST BE DISCONNECTED while the boiler is operating in
central heating mode. This will lock the valve motor in central heating
mode and ensure freeze protection operates properly. Failure to
disconnect the valve may disable boiler freeze protection and result
in property damage.
NOTICE
The use of glycol may reduce the usable BTU output of the boiler,
requiring the unit to be "down-fired" by limiting the maximum
operating capacity and/or water temperature. For applications
requiring glycol concentrations greater than 30%, such as snow melt
systems, it is recommended to use a brazed plate heat exchanger to
separate the glycol mixture from the boiler water. See below.
Snow
Brazed
melt
plate
system
hex
Figure 1 - Snow Melt Application
H. Water Temperature Adjustment and Scalding
This boiler can deliver scalding water. Be careful whenever using hot
water to avoid scalding injury. Certain appliances such as dishwashers
and automatic clothes washers may require increased water
temperatures. By setting the thermostat on this boiler to obtain the
increased water temperature required by these appliances you may
create the potential for scald injury.
To protect against injury, install a mixing valve in the water system.
This valve will reduce point of use discharge temperatures by mixing
cold and hot water in branch supply lines. Such valves are available
from your local plumbing supplier.
DANGER
An ASSE 1017 or ASSE 1070 temperature limiting or mixing valve
is required in all combi boiler installations. Failure to install a
temperature limiting or mixing valve will result in property damage,
severe personal injury, or death due to scalds.
TRX Series 2 - Installation - Startup - Maintenance Instructions
M
Air-eliminator
Make-up
water
Backflow
preventor Exp.
Tank
Pressure
regulator
Y-Strainer
Part 1 - General Safety Information
Table 3 details the relationship of water temperature and time with
regard to scald injury and may be used as a guide in determining the
safest water temperature for your applications.
Approximate Time / Temperature Relationships in
120 F
o
125 F
o
130 F
o
135 F
o
140 o F
145 F
o
150 F
o
155 F
o
Table 3 - Time and Temperature Relationship in Scalds
I. High Elevation Installations
This boiler is designed to operate at its maximum listed capacity in
installations located at 0 - 2000 ft above Sea Level. Since the density
of air decreases as elevation increases, maximum specified capacity
should be de-rated for elevations above 2000 ft (610 m) in accordance
with the table below.
2001 ft 3000 ft
Elevations
(610 m) (914 m)
In Canada 1 ,
10% 10%
de-rate by:
In USA 2 ,
- 12%
de-rate by:
NOTES:
1 Canada: Elevations between 2000 - 4500 ft (610 - 1372 m), de-rate by 10%.
Consult local authorities for de-rating for elevations above 4500 ft (1372 m).
2 USA: If elevation is above 2000 ft (610 m), de-rate capacity by 4% for every
1000 ft (305 m).
Table 4 - De-Rate % for High Elevations
WARNING
Combustion - At elevations above 2000 ft, the combustion of the boiler
must be checked with a calibrated combustion analyzer to ensure
safe and reliable operation. It is the Installer's responsibility to
check and adjust the combustion in accordance with this
manual. Failure to follow these instructions may result in property
damage, serious personal injury, or death.
Scalds
More than 5 minutes
1 1/2 to 2 minutes
About 30 seconds
About 10 seconds
Less than 5 seconds
Less than 3 seconds
About 1 1/2 seconds
About 1 second
4000 ft 4500 ft 5000 ft
(1219 m) (1372 m) (1524 m)
10% 10% may vary
16% 18% 20%
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