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static pressure in the unit-duct system increases and to IN-
CREASE when the static pressure in the unit-duct system de-
creases (and fan airflow rate increases). Motor overload condi-
tions typically develop when the unit is operated with an access
panel removed, with unfinished duct work, in an economizer-
open mode, or a leak develops in the duct system that allows a
bypass back to unit return opening.
CONDENSER FAN MOTOR PROTECTION
The condenser fan motor is internally protected against over
temperature.
Control Circuit, 24-v
The control circuit is protected against overcurrent conditions
by a circuit breaker mounted on control transformer TRAN.
Reset is manual.
The factory-installed PremierLink Controller includes the sup-
ply-air temperature (SAT) sensor. The outdoor air temperature
(OAT) sensor is included in the FIOP/accessory EconoMi$er 2
package.
NOTE: Refer to
PremierLink™ Installation, Start-Up and Config-
uration Instructions
. Have a copy of this manual available at unit
startup.
PREMIERLINK CONTROL
For details on operating 48HC units equipped with the factory-
installed PremierLink controller option, refer to the
Premier-
Link Retrofit Rooftop Controller Version 3.x Installation, Start-
Up, and Configuration Instructions
manual.
RTU-OPEN CONTROL SYSTEM
For details on operating 48HC units equipped with the factory-
installed RTU Open controller, refer to the
“Factory-Installed
RTU Open Multi-Protocol Controller Control, Start-Up, Oper-
ation and Troubleshooting”
manual.
GAS HEATING SYSTEM
General
The heat exchanger system consists of a gas valve feeding mul-
tiple inshot burners off a manifold. The burners fire into match-
ing primary tubes. The tubes exit into the collector box, the
into the induced draft fan wheel inlet. The induced fan wheel
discharges into a flue passage and flue gases exit out a flue
hood on the side of the unit. The induced draft fan motor in-
cludes a Hall Effect sensor circuit that confirms adequate
wheel speed through the Integrated Gas Control (IGC) board.
Safety switches include a Rollout Switch mounted at the top of
the burner compartment. A limit switch is mounted through the
side of the fan deck over the tubes. The vestibule plate faces
the tubes. See Fig. 39-41.
Fig. 39 — Burner Section Details
Fig. 40 — Inducer Assembly
Fig. 41 — Limit Switch Locations
Fuel Types and Pressures
NATURAL GAS
The 48HC unit is factory-equipped for use with natural gas
(NG) fuel at elevation under 2000 ft (610 m). See section Ori-
fice Replacement on page 38 for information in modifying this
unit for installation at elevations above 2000 ft (610 m).
Gas line pressure entering the unit’s main gas valve must be
within specified ranges. See Table 9. Adjust unit gas regulator
valve as required or consult local gas utility.
Manifold pressure is factory-adjusted for NG fuel use. Adjust
as required to obtain best flame characteristic. See Table 10.
Table 8 — Overcurrent Device Type
MOTOR SIZE (bhp)
OVERLOAD DEVICE
RESET
1.7
Internal Linebreak
Automatic
2.4
Internal Linebreak
Automatic
2.9
Thermik
Automatic
3.7
Thermik
Automatic
4.7
External
(Circuit Breaker)
Manual
ROLLOUT
S
WITCH
GA
S
VALVE
S
PARK
IGNITER
FLAME
S
EN
S
OR
CAPACITOR
INDUCER
HOU
S
ING
INDUCER
WHEEL
INDUCER
COOLING FAN
INDUCER
MOTOR
LIMIT
S
WITCH FOR
S
IDE
S
HOT
LIMIT
S
WITCH
FOR DOWN
S
HOT
Содержание WeatherMaster Puron 48HC D17
Страница 18: ...18 COOLING CHARGING CHARTS Fig 22 Cooling Charging Chart 15 Ton ...
Страница 19: ...19 Fig 23 Cooling Charging Chart 17 5 Ton ...
Страница 20: ...20 Fig 24 Cooling Charging Chart 20 Ton ...
Страница 21: ...21 Fig 25 Cooling Charging Chart 25 Ton ...
Страница 37: ...37 Fig 48 Unit Control Box IGC Location IGC Board IGC Board Side view Front view ...
Страница 40: ...40 Fig 51 Typical IGC Wiring Diagram ...
Страница 46: ...46 Fig 57 RTU Open Overlay for Economizer Wiring ...
Страница 47: ...47 Fig 58 VFD Overlay for W2770 Controller Wiring ...
Страница 84: ...84 Fig B 48HC D17 D28 Control Diagram 208 230 3 60 460 575 3 60 ...
Страница 85: ...85 Fig C 48HC D17 D28 Power Diagram 208 230 3 60 ...
Страница 86: ...86 Fig D 48HC D17 D28 Power Diagram 460 3 60 ...
Страница 87: ...87 Fig E 48HC D17 D28 Power Diagram 575 3 60 ...
Страница 88: ...88 Fig F 48HC D17 D28 Control Diagram with Humidi MiZer System ...
Страница 89: ...89 Fig G 48HC D17 D28 Power Diagram 208 230 3 60 with Humidi MiZer System ...
Страница 90: ...90 Fig H 48HC D17 D28 Power Diagram 460 3 60 with Humidi MiZer System ...
Страница 91: ...91 Fig I 48HC D17 D28 Power Diagram 575 3 60 with Humidi MiZer System ...
Страница 92: ...92 Fig J PremierLink System Control Wiring Diagram 50HE500891 F ...
Страница 93: ...93 Fig K PremierLink System Control Wiring Diagram with Humidi MiZer System ...
Страница 94: ...94 Fig L RTU OPEN Wiring Diagram ...
Страница 95: ...95 Fig M RTU OPEN Wiring Diagram with Humidi MiZer System ...
Страница 97: ......