Specifications
15
Limit in effect, no call for cooling due to no load, and alarm or
alert conditions present. If the machine should be running and
none of the above are true, a minimum off time (DELY, see
below) may be in effect. The machine should start normally
once the time limit has expired.
MINUTES OFF TIME (Configuration
OPT2
DELY) — This user-configurable time period is used by the
control to determine how long unit operation is delayed after
power is applied/restored to the unit. Typically, this time period
is configured when multiple machines are located on a single
site. For example, this gives the user the ability to prevent all
the units from restarting at once after a power failure. A value
of zero for this variable does not mean that the unit should be
running.
CAPACITY CONTROL OVERRIDES — The following over-
rides will modify the normal operation of the routine.
Deadband Multiplier
— The user configurable Deadband
Multiplier (Configuration
SLCT
Z.GN) has a default
value of 1.0. The range is from 1.0 to 4.0. When set to other
than 1.0, this factor is applied to the capacity Load/Unload
Factor. The larger this value is set, the longer the control will
delay between adding or removing stages of capacity. Figure
11 shows how compressor starts can be reduced over time if
the leaving water temperature is allowed to drift a larger
amount above and below the set point. This value should be set
in the range of 3.0 to 4.0 for systems with small loop volumes.
Figure 12 shows the operating envelope for the compressor.
First Stage Override
— If the current capacity stage is zero,
the control will modify the routine with a 1.2 factor on adding
the first stage to reduce cycling. This factor is also applied
when the control is attempting to remove the last stage of
capacity.
Slow Change Override
— The control prevents the capacity
stages from being changed when the leaving fluid temperature
is close to the set point (within an adjustable deadband) and
moving towards the set point.
CEBD430351-0396-01C
TEST 1
CEPL130351-01
PWR
TEST 2
J1
J2
J4 J3
J5
J6
J7
LEN
STATUS
RED LED - STATUS
GREEN LED -
LEN (LOCAL EQUIPMENT NETWORK)
ADDRESS
DIP SWITCH
Fig. 10 — Energy Management Module