Raypak 5000.72A, Installation & Operating Instructions Manual

Page: 43 / 80

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Priority Override Time (PRI OVR)
This selects the length of time for the priority override.
This value is only available for set/change when the
PIM™ identity is “H” or DHW PRIORITY = ON. The
settings can be “Au” or from 10 min to 2.0 hours. The
default value is “1:00 hr”. This will maintain the priori-
ty override until the call-for-heat in this system is
satisfied.
Cold Water Protection (CWP)
Some applications require reliable protection against
harmful condensation caused by frequent, extended,
cold water exposure. The CWP system utilizes sever-
al piping configurations with proportional 3-way valve,
2-way valve or injection VS pump system to maintain
the inlet water temperature to the unit during operation
in order to prevent harmful condensation.
The applicable settings for this operation are enabled
and shown within the SETUP menu when the VERSA
®
board DIP switch # 3 is enabled.
The following are the settings for the CWP:
MIX Type (H and WH) •
MIX Target •
MIX Lock •
MIX Speed •
MIX Inv •
MIX Trim •
MIX Type
For Hydronic systems MIX Type has two options,
“BOIL” and “PLNT”.
“BOIL” assumes that each individual unit will have the
proper wiring and pipe configuration to control its own
inlet temperature. (see figure 10 page 10)
“PLNT” assumes that a 3-way valve will control the
inlet temperature among the entire system (cascade).
(see figure 13 page 13)
For Domestic hot water systems (WH) Mix Type has
two options, “1” and “2”.
"1" is used for configuration with potable approved pro-
portional valve (2-way or 3-way, model dependent).
"2" is used for configuration with variable-speed injec-
tion pump. (see fig 25 page 28)
MIX Target
This is the control setpoint for inlet temperature, the
default setting is 120F. Consult the product-specific
manual for required minimum inlet temperature for
proper operation.
MIX Lock
The equipment will trigger a warning when “MIX
Target” is not reached within 7 minutes. MIX Lock
defines whether the system will alarm and continue
running or will alarm and lockout the unit. MIX Lock
“ON” will shut the unit down and provide an alarm if the
inlet temperature is not achieved within 7 minutes,
requiring manual reset. MIX Lock “OFF” will only pro-
vide an alarm contact closure while allowing the unit to
remain operational if the inlet temperature is not
achieved within 7 minutes.
MIX Speed
This setting defines speed of response. The default
setting of MED has been found to provide stable oper-
ation in most piping configurations. Depending on
product selection and mix of sizes (cascade) the set-
ting can be adjusted to fine-tune the CWP operation.
MIX Inv
This option is related to the use of spring-return actu-
ators with a proportional 2 or 3-way valve for CWP.
Valve actuators can be field configured to provide
spring-to-system or spring-to-bypass operation,
depending on user preference. This output can be
configured for MIX INV “OFF” 0 to 10 VDC (0% to
100%), or MIX INV “ON” 10 to 0 VDC (0 % to 100%).
MIX Trim
This item allows adjustment for various types and
sizes of units as well as various actuator motor speeds
and types supplied by Raypak. For systems with very
cold start up temperatures such as snow melt / deicing
the trim may require adjustment to lower values for
stable operation. For the majority of the systems with
CWP the default value of zero will provide stable oper-
ation.
Temperature Units of Measure
(°F or °C)
This selects the units of measure to show on the dis-
play. The choices are degrees Fahrenheit (°F) and
degrees Celsius (°C). The default is degrees
Fahrenheit (°F).
WARNING: A MIX Target setting below the mini-
mum required for the product being used will cause
damage from harmful condensation.
WARNING: Operating below the minimum inlet
required for the product being used will cause dam-
age from harmful condensation.