Carrier 30WG 080 - 5.5 - Operating limits 30 WGA

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5.7 - Minimum chilled water ow
If the system water ow rate is lower than the minimum water
ow rate, recirculation of the evaporator ow may occur. The
temperature of the mixture leaving the evaporator must
never be less than 2.5 K lower than the chilled water entering
temperature.
5.8 - Maximum chilled water ow
The maximum chilled water ow is limited by the maximum
permitted pressure drop in the evaporator. It is provided in
the tables in chapter 5.7. If the ow exceeds the maximum
value, two solutions are possible:
• Modify the ow rate with a control valve.
• Bypass the evaporator to obtain a highter temperature
difference with a lower evaporator ow rate.
5.9 - Variable ow
A pump with variable ow can be used in these units. The
units maintain a constant leaving water temperature under
all ow conditions. For this to happen, the minimum ow
rate must be higher than the minimum ow given in the table
of permissible ow rates and must not vary by more than
10% per minute.
If the ow rate changes more rapidly, the system should
contain a minimum of 6.5 litres of water per kW instead of
the values below.
30WG Minimum Maximum
Evaporator
Entering water temperature at start-up °C 7.5* 27
Leaving water temperature during operation °C 5** 20
Entering/leavingwatertemperaturedifference K 2,5 7
Air entering temperature (at start-up and during operation)***
Airenteringtemperature(xed-speedfan) °C 0*** 35to48‡
Airenteringtemperature(variable-speedfan) °C -10 to -20† 35to48‡
* Forenteringwatertemperaturesbelow7.5°Catstart-up,contactCarrier.
** 30WGAunitcanoperatedownto0°Cifthecongurationoftheuidtypeused
ismodied.Iftheleavingwatertemperatureisbelow5°C,afrostprotection
solutionmustbeused.
*** The minimum temperature range is based on the condenser selected. If
the condenser onlyhas afew fan stages, the use of variable-speedfans is
recommendedfrom10°C.
† Theminimumtemperaturerangeisbasedonthecondenserselected.
‡ Themaximumtemperaturerangeisbasedonthecondenserselected.
5.6 - Operating range 30WGA
20
25
30
35
40
45
50
55
60
65
-2 0 2 4 6 8 10 12 14 16 18 20
 30WGAstandardunit
 30WGAunitformediumtemperatureapplication(%glycol<25%)
Evaporatorleavingwatertemperature,°C
Condensingtemperatre,°C
Standard
Medium
temperature
application
5.5 - Operating limits 30WGA 5.10 - Water ow rates
5.10.1 - Standard 61WG
61WG Evaporator water ow rate, l/s
Minimum* Minimum** Maximum*** Maximum****
Low
pressure
High
pressure
Low
pressure
High
pressure
020 1.0 0.9 0.5 3.1 3.6 3.8
025 1.0 1.0 0.5 3.3 3.8 4.1
030 1.0 1.0 0.5 3.3 3.8 4.1
035 1.1 1.1 0.6 3.6 4.2 4.7
040 1.2 1.1 0.6 3.8 4.4 5.0
045 1.2 1.1 0.8 4.0 4.6 5.4
050 1.6 1.4 0.8 5.4 7.8 9.2
060 1.5 1.6 1.0 6.1 8.0 9.9
070 1.6 1.5 1.1 6.2 8.1 10.3
080 1.6 1.5 1.3 6.3 8.3 10.9
090 2.0 1.6 1.5 7.8 8.7 12.5
* Units with hydronic module
Flow rate for a maximum permitted temperature difference at the minimum
leaving water temperature
** Units without hydronic module
Flow rate for a maximum permitted temperature difference at the minimum
leaving water temperature
*** Units with hydronic module
 Maximumowrateforanavailablepressureof20kPa(unitwithlow-pressure
hydronic module) or 50 kPa (unit with high-pressure hydronic module)
**** Units without hydronic module
 Maximumowrateforapressuredropof100kPaintheplateheatexchanger.
61WG Condenser water ow rate, l/s
Minimum* Maximum** Maximum***
Low pressure High pressure
020 0.3 3.1 3.5 3.8
025 0.3 3.3 3.8 4.1
030 0.3 3.3 3.8 4.1
035 0.4 3.5 4.1 4.7
040 0.4 3.7 4.3 5.0
045 0.4 3.9 4.5 5.4
050 0.4 4.8 6.8 7.0
060 0.5 5.5 7.0 7.5
070 0.5 5.6 7.2 7.8
080 0.6 5.8 7.4 8.2
090 0.6 7.2 7.9 9.3
* Units with or without hydronic module
 Minimumowrateforawatertemperaturedifferenceof18K-
 Note:Operationpermitteduptoavalueof20K.
** Units with hydronic module
 Maximumowrateforanavailablepressureof20kPa(unitwithlow-pressure
hydronic module) or 50 kPa (unit with high-pressure hydronic module)
*** Units without hydronic module
 Maximumowrateforapressuredropof100kPaintheplateheatexchanger
5.10.2 - 61WG with option 272
61WG Minimum evaporator glycol solution ow rate - option 272*, l/s
Minimum** Minimum***
Low pressure High pressure
020 0.5 0.5 0.5
025 0.5 0.5 0.5
030 0.5 0.5 0.5
035 0.6 0.6 0.6
040 0.6 0.6 0.6
045 0.8 0.8 0.8
050 2.0 1.9 0.8
060 1.9 1.9 1.0
070 1.9 1.9 1.1
080 1.9 2.0 1.3
090 2.2 2.0 1.5
* Option 272: Condenser side high-temperature water production, evaporator side
with glycol solution,
** Units with hydronic module
 Minimum ow rate for a maximum permitted temperature difference at the
minimum leaving water temperature
*** Units without hydronic module
 Minimum ow rate for a maximum permitted temperature difference at the
minimum leaving water temperature