Trane CITY RTSF Series Manual page 20

Installation - Mechanical
Condenser water pump with variable frequency drive – Figure 4
Advantages:
• Pumping cost can be reduced. Good cooling device temperature control.
• Relatively low fi rst cost.
Disadvantage:
• Increased rate of fouling due to lower water velocity in the condenser.
Figure 4
CO
CDS
7
CI
5B
4
8
EO
EVP
EI
1 = Electric valve actuator
2A = 3-way valve or 2 butterfl y valves
2B = 2 butterfl y valves
3 = RTSF controller
4 = Refrigerant pressure line
5A = Condenser water pump
5B = Condenser water pump with VFD
6 = To/from cooling load
7 = To/from cooling device
8 = Electric controller
EI = Evaporator Inlet
EO = Evaporator Outlet
CI = Condenser Inlet
CO = Condenser Outlet
Condenser Water Regulating Valve Adjustment
A separate Settings Menu tab entitled "Condenser Head Pressure Control -Setup" that is only visible if the
confi guration is selected, contain the following settings and manual overrides for user adjustments and
commissioning all under one tab:
• "Off State" Output Command (0-10 Vdc, 0.1 volt increments, Default 2.0 Vdc)
• Output Voltage @Desired Minimum Flow (Adj: 0 to 10.0 in 0.1 volt increments, Default 2.0 Vdc)
• Desired Minimum Flow (Adj:0-100% of full fl ow in 1%intervals, Default 20%)
• Output Voltage @Desired Maximum Flow (Adj: 0 to 10.0 in 0.1 volt increments (or fi ner),Default 10 Vdc)
• Actuator Stroke Time (Min to Max Range Time)(Adj: 1 to 1000 seconds, in 1 second increments, Default 30s)
• Damping Coeffi cient (adj: 0.1 to 1.8, in 0.1 increments, Default .5)
• Head Pressure Control Override (enumeration of: disabled (auto), " off" state, minimum, maximum (100%),) default :
disabled (auto). When this setting is in "disabled (auto)"
• Condenser Water Pump Prerun Time
WARNING: In low temperature chilled water applications, in the case of a power loss, there is a risk of a condenser
freeze-up. For low temperature chilled water applications, it is recommended to take freeze protection measures.
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RLC-SVX023B-GB