Description Of The Input Menu - Carrier 30GX Installation, Operation And Maintenance Instructions

However, the reset parameters remain
accessible to any type of configuration
and make it possible to obtain any
combination of slope and reset origin in
response to fluctuations in the value of
D
T on the active heat exchanger.
D
Reset based on T is a linear function
which requires three parameters to be
configured:
D
• A reference T at which the reset is
D
zero: this is the T for zero reset
referred to in item 10 for cooling mode
or item 15 for heating mode.
D
• A reference T at which the reset is at
D
maximum: this is the
reset referred to in item 11 for cooling
mode or item 16 for heating mode.
• The maximum reset value: this is the
maximum reset value referred to in item
12 for cooling mode - item 17 for
heating mode.
D
Range: T for zero reset:
0 to 13.8°C
D
T for maximum reset:
0 to 13.8°C
Maximum reset value:
-16.6 to 16.6°C
The reset is calculated as follows if the
D
value of the T for zero reset exceeds the
D
value of the T for maximum reset
(negative slope):
• The reset is zero if the current
exceeds the reference value
reset.
• The reset equals the maximum reset
D
value if the current T is lower than the
D
reference value T for maximum reset.
D
• If the current T is between the
D
reference values T for zero reset and
D
T for maximum reset, the reset value
is calculated by linear interpolation
between the maximum reset value and
0.
The reset is calculated as follows if the
D
value of the T for zero reset is lower
D
than the value of the T for maximum
reset (positive slope):
• The reset is zero if the current
lower than the reference value
zero reset.
• The reset equals the maximum reset
D
value if the current T exceeds the
D
reference value T for maximum reset.
D
• If the current T is between the
D
reference values T for zero reset and
D
T for maximum reset, the reset value
is calculated by linear interpolation
between 0 and the maximum reset
value.
T for maximum
D
T
D
T for zero

4.2.8 - Description of the INPUT menu

This menu displays the status of the controller inputs. Access
to this menu is read-only.
ITEM
0
1
2*
3*
4
5
6
7
8
D
9
T is
10
D
T for
11
12
13
14
Key:
* : This item is displayed in certain unit configurations only.
D
Sample T reset configuration:
In this example, the cooling setpoint starts
to be reset with effect from a
evaporator of 5.0°C (full load) up to a
maximum reset of 3°C at a
This example assumes that the:
• Reset based on
configured in the configuration menu (see
section 4.2.10, configuration).
The configuration shall be as follows:
• Zero reset if the evaporator
zero reset - Item 10) is greater than 5.0°C;
• Maximum reset 3°C (Maximum reset
value - Item 12) if the evaporator
D
T for maximum reset - Item 11) is lower
than 3.0°C.
The setpoint curve is then as follows:
Cooling setpoint
MAXIMUM RESET VALUE
D
T FOR MAXIMUM RESET
D
T RESET REFERENCE VALUE
FORMAT DESCRIPTION
open/close Remote start/stop contact status
open/close Remote cooling setpoint selection contact status
open/close Remote heat/cool selection contact status
open/close Remote reclaim mode selection contact status
open/close Demand limit contact status
open/close Evaporator water flow control contact status
open/close Condenser water flow control contact status
open/close Oil level control contact status circuit A
open/close Oil level control contact status circuit B
nn Heat reclaim condenser water flow control contact status
nn Drain pressostat contact status, circuit A
nn Drain pressostat contact status, circuit B
nn Evaporator liquid refrigerant level circuit A
nn Evaporator liquid refrigerant level circuit B
nnn 0-10 V d.c signal
D
T at the
D
T of 3.0°C.
D
T has already been
D D
T (i.e. T for
D
T (i.e.
D
T reset
D
T FOR ZERO RESET
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