Trane Technologies Tracer TD7 - Hot Water Reset (HWR); HWR Functional Description; HWR Outdoor Air Reset Calculation

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11UNT-PRC002-GB
Sound power levels
Discharge
Measurement conditions:
Measurements taken in a room adjacent to the room containing the FWD, at the outlet of the rectangular duct (1.5 m
long) fixed to its discharge opening.
Fan Power level in dB(A), per Hz frequency band Overall power
Unit speed 125 250 500 1000 2000 4000 8000 dB(A)
1 55 50 42 37 37 31 30 46
FWD 08 2 57 54 47 40 30 38 40 50
3 58 57 50 42 32 40 43 53
1 57 51 45 42 34 33 28 48
FWD 10 2 58 54 48 45 38 39 35 51
3 60 58 50 48 40 42 39 54
1 57 51 45 42 34 33 28 48
FWD 12 2 58 54 48 45 38 39 35 51
3 60 58 50 48 40 42 39 54
1 56 62 50 48 39 38 36 56
FWD 14 2 61 66 55 53 47 46 45 60
3 63 69 58 56 50 50 49 63
1 57 63 51 49 40 39 37 57
FWD 20 2 61 66 55 53 47 46 45 60
3 63 69 58 56 50 50 49 63
Intake
Measurement conditions:
Measurements taken at the horizontal air intake.
Fan Power level in dB(A), per Hz frequency band Overall power
Unit speed 125 250 500 1000 2000 4000 8000 dB(A)
1 56 55 55 53 46 45 42 57
FWD 08 2 63 62 60 60 53 53 53 64
3 66 65 63 62 56 55 57 67
1 62 58 55 58 51 48 44 61
FWD 10 2 66 63 60 62 56 55 52 66
3 70 67 63 65 59 59 57 69
1 62 58 55 58 51 48 44 61
FWD 12 2 66 63 60 62 56 55 52 66
3 70 67 63 65 59 59 57 69
1 66 65 65 65 57 50 46 68
FWD 14 2 73 72 69 71 64 59 57 74
3 78 76 73 75 69 64 63 78
1 68 72 64 64 56 52 50 69
FWD 20 2 76 76 68 71 65 61 61 75
3 78 79 71 74 69 66 66 78
CG-SVU010C-GB
Hot Water Reset
Hot Water Reset (HWR) - CXAF only
Functional Description
The UC800 shall reset the hot water temperature setpoint based on outdoor air temperature.
The hot water reset settings are as follows:
1. Reset Type – The following options are selectable: No Hot Water Reset, or Outdoor Air Temperature Reset.
2. Reset Ratio – both positive or negative reset ratios will be allowed.
3. Start Reset
4. Maximum Reset
Variable definitions:
HWS – Arbitrated hot water setpoint , before any reset has occurred
HWS’ – Active hot water setpoint, includes the effect of hot water reset
HWR – Amount of hot water reset (also called Degrees of Reset)
The above quantities are related by the equation:
HWS’ = HWS - HWR
or HWR = HWS – HWS’
With the chiller running and hot water reset enabled, HWR is allowed to change at a maximum rate of 1°F every 5
minutes until the actual HWR equals the desired HWR. When the unit is not running, actual HWR shall be set equal to
the desired HWR within one minute (no maximum rate is in effect).
If Hot Water Reset is disabled, desired HWR is 0.
Additional variables definitions:
RESET RATIO – User adjustable gain
START RESET – User adjustable reference
TOD – Outdoor Air Temperature
MAXIMUM RESET – User adjustable limit providing the maximum amount of reset
The equation for Outdoor Air Temperature Reset:
HWR = RESET RATIO * ( TOD – START RESET )
With limits:
HWR >= 0
HWR <= Maximum Reset
Example of calculating reset for outdoor air Temp:
If:
Reset Ratio = 30%
Start Reset = 10°C
Maximum Reset = 5°C
TOD = 15°C