Natco Fire Coil 85, Инструкция по установке и эксплуатации

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Fire Coil 85 (500-2000)
Page 27
the controller to the desired operating set point. The
controller has an interstage differential that can be
adjusted from 3°F to 10°F. This allows the user to have
some control over how stage 2 and stage 1 call for heat
(
see Figure 22 ).
Because the Fire Coil 85 controller senses inlet
water and the manual reset high limit senses outlet water,
the high limit should be set 40-50°F higher than the
controller, to avoid nuisance lockout of the manual reset
high limit.
6.4 External Boiler Operations
If controlling the stages of the MT2 from an
external source (multiple boiler control, BAS, etc) the
"Local/Remote" selector switch above the terminal strip
must be placed in the "Remote" position. In this mode,
the controller that is mounted on the MT2 will no longer
have control of the unit. The 24V from the unit waits at
the input terminal, and the external control switches this
24V from the input terminal to the stage terminal.
6.5 Limit Controls
The manual reset high limit control is provided as
standard equipment on all heaters. An additional
automatic reset switch is optional.A high limit
temperature-sensing bulb is always located in the heater
outlet. Burners will automatically shut down whenever
overheating occurs.
pressure, the level of water in the expansion tank
should not exceed ¼ of the total, with the balance
filled with air.
9. Start up system according to the procedure in this
manual. Operate the entire system, including the
pump, boiler, and radiation units for one (1) hour.
10. Recheck the water level in the expansion tank. If
the water level exceeds ¼ of the volume of the
expansion tank, open the tank drain, and drain to
that level.
11. Shut down the entire system and vent all radiation
units and high points in the system piping, as
described in
Step 4 .
12. Close make-up water valve and check strainer in
pressure reducing valve for sediment or debris
from the make-up water line. Reopen make-up
water valve.
13. Check gauge for correct water pressure and also
check water level in the system. If the height
indicated above the boiler insures that water is at
the highest point in the circulating loop, then the
system is ready for operation.
14. Refer to local codes and the make-up water valve
manufacturer’s instructions as to whether the make-
up water valve should be left open or closed.
15. After placing the unit in operation, the ignition
system safety shutoff device must be tested. First,
shut off the manual gas valve, and call the unit for
heat. After the pre-purge and ignitor heat-up time,
the main gas terminals will be energized, attempting
to light, for four (4) seconds, and then will de-
energize. The unit will go into lockout mode.
Second, turn the power off and then on again, open
the manual gas valve and allow the unit to light.
While the unit is operating, close the manual gas
valve and ensure that power to the main gas valve
has been cut.
16. Within three (3) days of start-up, recheck all air
bleeders and the expansion tank as described in
Steps 4 and 8 above.
Important: The installer is responsible for identifying to
the owner/operator the location of all emergency shutoff
devices.
WARNING
Do not use this appliance if any part has been under
water. Immediately call a qualified service technician
to inspect the appliance
and to replace any part of the control system and any
gas control that may have been
under water.
6.3 Operating Temperature Control
All Fire Coil 85's are equipped with a two-stage
aquastat. To utilize this mounted controller be sure to
have the "Local/Remote" selector switch to "Local". Set
* 1 Difference between the temperatures at which the two switches
make R-W. Adjustable from 3°F to 10°F (1.7°C to 5.6°C) on standard
models, or from 3.6°F to 12°F (2.0°C to 6.7°C); 55°F to 175°F (13°C
to 79°C) models.
*
2 Two DPDT switches operate in sequence. Each switch
differential is fixed at approximately 3°F (1.7°C) on standard models,
or 3.6°F (2.0°C); 55°F to 175°F (13°C to 79°C) models.
Figure 22. Honeywell L8008G.