402 COMFORT CONTROL LOGIC

Questions

SUB BASE

Up to 16 wires may be requiredUp to 16 wires may be required

AUTO CHANGEOVER

• IF IDT ≥ CSP (minus 1) then: – COOLING MODE – ( SP = 75, COOL MODE to 74)

• IF IDT < HSP then: – HEATING MODE – (Dead Band factory set to 3 degrees)

LOAD VALUE

• Control reacts to LOAD VALUE

• Traditional PI– Calculated every two seconds– P = Δt– I = ΣΔt Ti

• P + I = LOAD VALUE

LOAD VALUE & STAGING

• LV determines – TURN ON threshold for each stage– TURN OFF threshold for each stage

• LV of 5 to turn ON– 5 minute Min OFF time for CLG– 1 minute Min OFF time for HTG

• Max LV limits are set by HVAC config.

LOAD VALUE & STAGING

CLG 0-100 Single Stage Compressor 0-200 Two Stage Compressor

HTG 0-100 Single Stage HP or Furnace 0-200 Two Stage HP or Furnace 0-200 Single Stage HP + 1 Stage Indoor Heat 0-300 Single Stage HP + 2 Stage Indoor Heat 0-400 Single Stage HP + 3 Stage Indoor Heat 0-300 Two Stage HP + 1 Stage ID Heat 0-400 Two Stage HP + 2 Stage ID Heat 0-500 Two Stage HP + 3 Stage ID Heat

LOAD VALUE & STAGING

3002000 100 400+

LV = Load Value

Calculated Every Two Seconds

INCREASED DEMAND

INCREASED DEMAND

Stage 1 Stage 2 Stage 3 Stage 4

Maximum LV Limits

are set by

HVAC Configuration

Stage 5

MULTI STAGE THRESHOLD

• Dead Band @ LV Threshold – to avoid cycling around LV

Increased Demand LV 0-110 1st StageLV >111 2nd Stage

Decreased Demand LV >100 2nd StageLV 99-0 1st Stage

10 Minute INHIBIT once Threshold is Crossed

2000 110

Stage 1 Stage 2

Cross LV Dead Band & Initiate10 Minute INHIBIT

(Does not apply to W1 to W2)

Stage 3

115 125

LV = Load Value

Begin INHIBIT - Y1 to Y2

Begin INHIBIT - HP to W1

Begin INHIBIT - HP to Dual Fuel

MULTI STAGE INHIBIT

TWO STAGE COMPRESSOR

Y1 “ON”

Start INHIBIT

Y2 “ON”

10 Min

LV = Load Value

LV 110

Y1 “ON”

LV 100

Y1 “ON”

Start INHIBIT

10 Min

LV = Load Value

LV 115LV 100

SINGLE STAGE HEAT PUMP with AUX HEAT

W1 “ON” W1 “OFF”

Y1 “ON”

Start INHIBIT

10 Min

LV 125

Y1 “ON”

DUAL FUEL EQUIPMENT

W1 “ON” 45 seconds cool down

LV 100

LV = Load Value

MULTI STAGE INHIBIT

If IDT is ½° or less from Set Point, the next stage is always INHIBITED regardless of LV

IDT

SP

1/2° INHIBIT 2nd stage Cooling

1/2°

SP

INHIBIT 2nd stage Heating

LV CLAMP

MAX OVERSHOOT = 2.5° F

Turns system “OFF” regardless of LV

System will turn back “ON” 3/4° from SP

•Provided Min OFF Time has elapsed

•Provided LV is still present

Max Overshoot not enforced during DROOP

COOLING DROOP

•Set Point is satisfied (No-load or light load condition)

•Time OFF satisfied

•IDT < Droop OVERSHOOT limit to start DROOP “ON” cycle

•Standard DROOP = 1 degree OVERSHOOT

•Enhanced DROOP = 2 degree OVERSHOOT

•Fan delay-to-OFF is cancelled

•Var Sp: Blower speed set to 80% (BK= 70% PWM)

•Minimum ON = 8 minutes

•Minimum OFF = 20 minutes

SET POINT CHANGES

• Temperature Display Rounds to Nearest Whole Number

• Room Sensor can Discern 10ths of a Degree – – Used to Calculate Temp Difference from SP

• Large Changes in SP will Freeze LV until New SP is Reached to Avoid Overshoot– “Snap Shot & Roll Back”

$

10 Min

Set PointIDT

5°

New Set Point

4°= AUX HT 3°= No AUX HT

Recovering IDT

ENERGY SAVINGS MODE

Rate of Recovery can increase INHIBIT

Only applies to Y1 to Y2 or HP to W1

Recovery Delta must be 1.25° to INHIBIT

Distance to New SP divided by 4 is the Recovery Delta

Y2 or W1Y

$

10 Min

Set PointIDT

10°

New Set Point

8°= AUX HT 7°= No AUX HT

Recovering IDT

ENERGY SAVINGS MODE

Rate of Recovery can increase INHIBIT

Only applies to Y1 to Y2 or HP to W1

Recovery Delta must be 2.5° to INHIBIT

Distance to New SP divided by 4 is the Recovery Delta

Y Y2 or W1

$

Set PointIDT

>2°

New Set Point

Recovering IDT

ENERGY SAVINGS MODE

Aggressive Recovery will cancel INHIBIT

Only applies to Y1 to Y2 or HP to W1

NO INHIBIT

ISU # 35 EnabledY Y2 or W1

HUMIDISTAT OPERATION

RH control with external Humidistat connected to input terminals H1 and H2

In COOLING MODE

Open signal triggers:

•Compressor “ON” cycle time is extended by 2 minutes•Fan “OFF” delay is cancelled •PSC motors “ON” delay calculated by previous “OFF” time •Fan CFM reduced by 20% -Variable Speed – if Room Temp is within 2º of SP

BALANCE POINTS

Outdoor Sensor Must be Installed

BALANCE POINTS

Outdoor Sensor Must be Installed

BLOWER PROFILES

BLOWER PROFILES

PSC Motors

BLOWER PROFILES

When ODT is below 87° F, Variable Speed Airflow is Reduced to 80%

WET HEAT

VAR SP

0-90sec at 35% Airflow

PSC and VAR SP Motors

WET HEAT

Single Stage Wet Heat

PSC Motor VAR SP MotorLV ≤ 100 W1 cycled based on LV W1 on, Airflow adjusted based on LV

Two Stage Wet Heat

PSC Motor VAR SP MotorLV < 100 W1 cycled based on LV W1 on, Airflow adjusted based on LV

LV > 100 W1 On, W2 cycle based on LV W1 On, Airflow set to 100%, W2 cycled based on LV

PSC

BK Disabled - ISU # 11VARIABLE SPEED

BK Enabled - ISU # 11

TWO STAGE COMPRESSORS

WARM AIR HEAT PUMP

402 Comfort Control

Heat Pump Connection Diagram