Bryant 577D----A Maximum Gas Flow Capacity, Outdoor Air Temperature Sensor OAT

Table 2 – Maximum Gas Flow Capacity*

NOMINAL	INTERNAL						LENGTH OF PIPE ft (m)†
IRON PIPE	DIAMETER	10	20	30	40	50	60	70	80	90	100	125	150	175	200
SIZE (IN.)	(IN.)	(3.0)	(6.1)	(9.1)	(12.1)	(15.2)	(18.3)	(21.3)	(24.4)	(27.4)	(30.5)	(38.1)	(45.7)	(53.3)	(61.0)
1/2	.622	175	120	97	82	73	66	61	57	53	50	44	40	—	—
3/4	.824	360	250	200	170	151	138	125	118	110	103	93	84	77	72
1	1.049	680	465	375	320	285	260	240	220	205	195	175	160	145	135
1---1/4	1.380	1400	950	770	600	580	530	490	460	430	400	360	325	300	280
1---1/2	1.610	2100	1460	1180	990	900	810	750	690	650	620	550	500	460	430

*Capacity of pipe in cu ft of gas per hr for gas pressure of 0.5 psig or less. Pressure drop of 0.5---IN. W.C. (based on a 0.60 specific gravity gas). Refer to Table 2 and NFPA 54/ANSI Z223.1.

{This length includes an ordinary number of fittings.

ROUTING CONTROL POWER WIRES

For detailed instruction on the low voltage connections to the User Interface (UI), refer to the UI installation guide.

Form a drip-loop with the control leads before routing them into the unit. Route the low voltage control leads through grommeted, low-voltage hole provided into unit (See Fig. 5 and 6). Connect user interface leads to unit control power leads as shown in Fig. 14.

The unit transformer supplies 24-v power for complete system including accessory electrical heater. Transformer is factory wired for 230-v operation. If supply voltage is 208-v, rewire transformer primary as described in Special Procedures for 208-v Operation section.

The furnace board is fused by a board-mounted automotive fuse placed in series with transformer SEC1 and R circuit. The C circuit of transformer circuit is referenced to chassis ground through a printed circuit run at SEC2 and gas valve grounding wire. Check to be sure control board is mounted securely using both factory-installed screws.

ACCESSORY INSTALLATION

A. Outdoor Air Temperature Sensor (OAT)

!CAUTION

EQUIPMENT OPERATION HAZARD

The installation of an outdoor air temperature sensor (OAT) using the Evolution control board OAT terminals is required. Many Evolution features (auto humidity control, comfort rollback, etc.) will be lost if the OAT is not connected.

For detailed mounting instructions for the OAT sensor, please refer installation instructions shipped with the OAT.

The OAT input is used to supply outdoor temperature data for system level functions and for temperature display on User Interface (UI). Using two wires of the field-supplied thermostat wire cable, wire the ends of the two black OAT pigtails. Wire the opposite ends of these two wires to the OAT provided with the UI. There is no polarity to be observed.

NOTE: Mis-wiring OAT inputs will not cause damage to either Evolution control or thermistor. If the thermistor is wired incorrectly, no reading will appear at UI. Re-wire thermistor correctly for normal operation.

B. Humidifier Connections

The furnace control board terminal marked HUM is provided for low voltage (24-vac) control of a humidifier. No humidistat is required as UI monitors indoor humidity.

When commanded to operate humidifier, the unit control will energize the HUM output to turn humidifier on and de-energize HUM output to turn humidifier off. Wire HUM and COM terminals directly to humidifier as shown in Fig. 14.

C. Electronic Air Cleaner

Electronic Air Cleaner terminals are provided on the Evolution Control Board (EAC-1 and EAC-2). While these terminals can be used to power a 230V EAC, it is recommended that any EAC be installed per the EAC installation instructions and connected separately to a standard 115V or 230V outlet with an airflow sensor to control operation of the EAC.

SPECIAL PROCEDURES FOR 208-V OPERATION Be sure unit disconnect switch is open.

Disconnect the black primary lead from the transformer. See unit wiring label (See Fig. 16 and 17).

Connect the black primary lead to the transformer terminal labeled 208-v.

577D-- -- A

13