Carrier 58ZAV operating instructions ÐAmp Draw Check With Ammeter

Recheck temperature rise. It must be within limits specified on unit rating plate. Recommended operation is at midpoint of rise or above.

3.Set thermostat heat anticipator.

The thermostat heat anticipation must be set to match the amp draw of the electrical components in the R-W circuit. Accurate amp draw readings can be obtained at thermostat subbase terminals R and W. Fig. 20 illustrates an easy method of obtaining the actual amp draw. The amp reading should be taken after the blower motor has started. See the thermostat manufacturer's instructions for adjusting the heat anticipator and for varying the heating cycle length.

NOTE: When using an electronic thermostat, set cycle rate for 3 cycles per hr.

THERMOSTAT SUBBASE TERMINALS WITH THERMOSTAT REMOVED (ANITICIPATOR, CLOCK, ETC.,

MUST BE OUT OF CIRCUIT.)

HOOK-AROUND

AMMETER

R Y W G

10 TURNS

FROM UNIT 24-V

CONTROL TERMINALS

EXAMPLE:	5.0 AMPS ON AMMETER	=	0.5 AMPS FOR THERMOSTAT
	10 TURNS AROUND JAWS		ANTICIPATOR SETTING

A96316

Fig. 20ÐAmp Draw Check With Ammeter

CHECK SAFETY CONTROLS

The flame sensor, gas valve, and pressure switch were all checked in the Start-up Procedures section as part of normal operation.

1.Check primary limit control.

This control shuts off the combustion control system and energizes the circulating-air blower motor if the furnace overheats.

The preferred method of checking the limit control is to gradually block off the return air after the furnace has been operating for a period of at least 5 minutes. As soon as the limit has shut off the burners, the return-air opening should be unblocked. By using this method to check the limit control, it can be established that the limit is functioning properly and operates if there is a motor failure.

2.Check blocked vent safeguard switch.

The purpose of this control is to permit the safe shutdown of the furnace during certain blocked vent conditions.

a.Disconnect power to furnace and remove vent connector from furnace outlet collar. Be sure to allow time for vent pipe to cool down before removing.

Copyright 1999 CARRIER Corp. · 7310 W. Morris St. · Indianapolis, IN 46231

b.Restore power to furnace and set room thermostat above room temperature.

c.After normal start-up, allow furnace to operate for 2 minutes, then block flue outlet 100 percent. Furnace should cycle off within 2 minutes.

d.Remove blockage and reconnect vent pipe to furnace outlet collar.

e.Wait 5 minutes and then reset blocked vent safeguard switch.

3.Check pressure switch.

This control proves operation of draft inducer blower.

a.Turn off 115-v power to furnace.

b.Remove control door and disconnect inducer motor lead wires from wire harness.

c.Turn on 115-v power to furnace.

d.Set thermostat to "call for heat" and wait 1 minute. When pressure switch is functioning properly, hot surface igniter should NOT glow and control diagnostic light flashes a status code 31. If hot surface igniter glows when inducer motor is disconnected, shut down furnace immediately. Determine reason pressure switch did not function properly and correct condition.

e.Turn off 115-v power to furnace.

f.Reconnect inducer motor wires, replace control door, and turn on 115-v power to furnace.

4.Check auxiliary limits (when used).

a.Turn off 115-v power to furnace.

b.Remove blower access door.

c.Disconnect red motor lead at blower speed selector. Mark terminal for proper reconnection.

d.Replace blower access door.

e.Turn on 115-v power to furnace. Be sure room thermostat is calling for heat.

f.Allow furnace to operate until auxiliary limit activates, but DO NOT operate furnace longer than 4 minutes.

g.If furnace operates for 4 minutes, check/replace limit switch(es).

h.Turn off 115-v power to furnace.

i.Remove blower access door.

j.Reconnect red motor lead, reset switch, and replace door.

k.Turn on 115-v power to furnace.

CHECKLIST

1.Put away tools, instruments, and clean up debris.

2.Verify manual reset switches have continuity.

3.Ensure blower and control access doors are properly installed.

4.Cycle test furnace with room thermostat.

5.Check operation of accessories per manufacturer's instruc- tions.

6.Review User's Manual with owner.

7.Leave literature packet near furnace.

58zav10s

Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.

Book		1	4	PC 101	Catalog No. 535-729	Printed in U.S.A.	Form 58ZAV-10SI	Pg 20	8-99	Replaces: 58ZAV-9SI
	Tab	6a	8a