Carrier 58ED - Burner Orifices; Step 7 - Make Electrical Connections

58ED,PB
Horizontal Gas-Fired Furnaces
HEATING & COOLING
Support all gas piping independent of the fui nace. For
propane gas, a tank regulator is required to reduce supply
pressure to 12-13 in. wg. For manifold pressure, see
Table 6.
Check all piping for leaks using soapy water and a
brush.
A CAUTION
Never use an open flame when testing for gas leaks!
Use a soap and water solution
A 1/8 in. NPT plugged tap accessible for test gage
connection must be installed immediately upstream of
the gas supply connection to the furnace if one is not
supplied on gas valve.
BURNER ORIFICES — The furnace is supplied with
standard orifices for the gas shown on the rating plate.
Table 6 shows combinations of heating values and
specific gravities for various fuels, from which proper
input may be obtained
Regardless of the type of gas used, when installation is
at an elevation of 2000 ft or more above sea level, orifices
may need to be changed, depending on local gas value.
For operation at elevations above 2000 ft, input ratings
should be reduced at the rates of 4% for each 1000 ft
above sea level. To change orifices, remove the burner
removal cover on the gas valve side of unit. Remove
manifold locking device and slide the manifold tray back
until each burner is clear of heat exchanger tube. See
Fig. 5 Pull the manifold tray forward until burners are
clear of furnace. Remove the locking device from each
burner and pull each burner back off the orifice.
A CAUTION
Take care when removing the pilot burner not to
damage the pilot gas line.
After removing orifices, ensure the new orifices are
seated properly and tightened. Replace burners correctly
and secure with the locking device before replacing and
securing the manifold assembly.
A CAUTION
The manifold must be properly positioned in order
to engage the locking mechanism
Table 6 — Burner Orifices
TYPE OF GAS
(Heating Value — SP GR)
BTU PER CU FT
ORIFICE SIZE
(Drill No.)
NATURAL — MANIFOLD PRESS. 3.5 in. wg
800 — 0.6
43
900 — 0.6
44
1000 - 0.6
45
1100 - 0.6
46
PROPANE — MANIFOLD PRESS. 10 in. wg
2500 — 1.53
54
Fig. 5 — Burners Removed From Furnace
After securing the manifold assembly, replace all other
components and/or wiring, being sure that all connec¬
tions and screws are tightened.
A WARNING
If it is necessary to adjust the manifold pressure
more than 0.3 in. wg, the orifices must be changed
A WARNING
Never set the furnace input rate above that shown
on rating plate.
Use the following formula to determine the furnace
input rate:
Input (Btuh) = Heating Value of Gas (Btu/cu ft)
_ x 7200 sec/2 hr _
Time in sec for 2 cu ft of gas
Example. If the heating value of natural gas is 1015
Btu/cu ft and it takes 75 seconds to burn 2cuft of gas,
then:
Input (Btuh) = 1015 Btu/cu ft x 7200 sec/2 hr
75 sec/2 cu ft
Input = 97,440 Btuh
When checking rate, make sure all other gas appliances
are shut off except for pilot burners.
Step 7 — Make Electrical Connections — The
control system depends on the correct polarity of the
power supply. Connect field power wiring and field
ground wire as shown in Fig. 6 and 7.
A WARNING
The unit cabinet must have a separate uninterrupted
or unbroken electrical ground to minimize personal
injury if an electrical fault should occur.
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Bookll 14 PC101 Catalog No 535-834 PrintedinUSA Form 58ED,PB-1SI Pg6 6-85 Replaces: 58PB-1SI
Tab 16a 18a For replacement items use Carrier Specified Parts