Daikin DC80SN User Manual

Service Instructions
RSD6621010
July 2021
Copyright © 2021
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
This manual is to be used by qualied, professionally trained
HVAC technicians only.
Daikin does not assume any responsibility for property dam-
age or personal injury due to improper service procedures or
services performed by an unqualied person.
The material in this manual does not supersede manufactur-
ers installation and operation instructions.

Daikin DC80SN Specifications

General

Brand	Daikin
Model	DC80SN
Category	Furnace
Language	English

Summary

Document Overview and Important Information

Understanding Safety Symbols and Labels

Guidance on understanding safety indicators and labels within the manual.

Operating Instructions

Pre-Operation Safety Warnings

Critical safety precautions to prevent fire, explosion, or injury during operation.

General Safety Guidelines

General Safety Precautions

Adherence to warnings and cautions for installation, adjustment, alteration, service, or operation.

ESD Precautions for Control Modules

Steps to protect integrated control modules from static discharge damage.

Propane Gas and High Altitude Installations

Conversion Kit Requirements

Necessity of correct conversion kits for propane gas and high altitude installations.

Furnace Startup Procedure

Gas Heat Sequence of Operation

Call for Heat Process

Step-by-step process initiated by a thermostat call for heat.

Cooling Mode Sequence of Operation

Operation sequence for low and high stage cooling modes.

Polarization and Phasing

Importance of Power Polarization and Phasing

Explanation of why incoming power polarization and phasing are critical for electronics.

Checking Transformer Phasing

Procedure for testing transformer phasing for correct operation.

Maintenance Procedures

Annual Inspection

Flame Sensor Maintenance

Heating Performance Test

Calculating BTU Input

Servicing Procedures

Voltage Checks (S-1)

Procedure for verifying voltage levels at various points in the furnace.

Wiring Checks (S-2)

Thermostat and Wiring Checks (S-3A)

Transformer and Control Circuit Checks (S-4)

Circulator Blower Motor Checks (S-16)

Duct Static Checks (S-200)

Temperature Rise Checks (S-201)

Primary Limit Control Check (S-300)

Testing the function of the primary limit control for safety.

Auxiliary Limit Control Check (S-301)

Testing the auxiliary limit control for safety operation.

Flame Rollout Control Check (S-302)

Verifying the operation of the flame rollout safety control.

Induced Draft Blower Motor Check (S-303)

Gas Valve Check (S-304)

Procedures for checking the redundant operator gas valve functions.

Main Burner Checks (S-305)

Gas Pressure Checks (S-307)

Measuring and adjusting inlet and manifold gas pressures.

Hot Surface Ignitor Check (S-308)

Flashback Checks (S-309)

Pressure Switch Check (S-310)

Testing the pressure switch for correct operation and activation.

Delayed Ignition Check (S-312)

Ignition Control Board Check (S-313)

Flame Sensor Check (S-314)

Testing the flame sensor for proper micro-amp signal and continuity.

Airflow Tables