19
Shorting the jumpers for a period of 5 to 20 seconds bypasses
the remaining continuous run period and places the unit in a
Forced Defrost mode. If the controlling DFT is closed when
this mode is initiated, the unit will complete a normal defrost
period that will terminate when the controlling DFT opens or
the 10 minute defrost cycle limit is reached. If the controlling
DFT is open when this mode is initiated, the Defrost cycle will
run for 30 seconds. Both modes end at the end of the Defrost
cycle.
ELECTRIC HEATERS
The 547K*14 units may be equipped with field-installed
accessory electric heaters. The heaters are modular in design,
with heater frames holding open coil resistance wires strung
through ceramic insulators, line-break limit switches and a
control contactor.
Heater modules are installed in the compartment below the in
-
door (supply) fan outlet. Access is through the electric heat
access panel. See Fig. 36-38.
Not all available heater modules may be used in every unit.
Use only those heater modules that are UL listed for use in a
specific size unit. Refer to the label on the unit cabinet for the
list of approved heaters.
Refer to the
Small Roof Top Units Accessory Electric Heater
and Single Point Box
installation instructions for further
details.
Fig. 36 — Access Panel Location
Fig. 37 — Component Location
Fig. 38 — Heater Module Installation
Control Box
Non-Fused
Disconnect*
* Factory-Installed Option.
Convenience
Outlet*
Single
Point Box
Center
Post
Control Wire
Terminal Block
Heater
(Cover Removed)
Heater Mounting
Bracket
Manual Reset
Limit Switch
Vane Axial
Indoor Fan System
Heater Module
Содержание Legacy 547K 14
Страница 4: ...4 Fig 2 547K 14 Unit Dimensional Drawing...
Страница 5: ...5 Fig 2 547K 14 Unit Dimensional Drawing cont...
Страница 8: ...8 Fig 5 547K 14 Roof Curb Details...
Страница 21: ...21 Fig 41 Typical Control Wiring Diagram Electromechanical with W7220 Controller...
Страница 22: ...22 Fig 42 Typical Power Wiring Diagram 208 230 460 3 60 Unit Shown...
Страница 23: ...23 Fig 43 Typical Power Wiring Diagram 575 3 60 Unit Shown...
Страница 41: ......