Instruction manual

5 4 Cool Only Control5 4 Cool Only Control
An ETR-3400 is used to control a refrigerator at temperature below 32 F. To
avoid the set point adjustment beyond the desired range, SP1L is set at
14 F and SP1H is set at 32 F. The temperature is lower than the ambient, a
cooling action is required. Hence select DIRT for OUT1. Since output 1 is
used to drive a magnetic contactor, O1TY selects RELY. A small
temperature oscillation is tolerable, hence use ON-OFF control to reduce
the over-all cost. To achieve ON-OFF control, PB1 is set with zero and O1HY
is set at 0.1 F.
An ETR-3400 is used to control a refrigerator at temperature below 32 F. To
avoid the set point adjustment beyond the desired range, SP1L is set at
14 F and SP1H is set at 32 F. The temperature is lower than the ambient, a
cooling action is required. Hence select DIRT for OUT1. Since output 1 is
used to drive a magnetic contactor, O1TY selects RELY. A small
temperature oscillation is tolerable, hence use ON-OFF control to reduce
the over-all cost. To achieve ON-OFF control, PB1 is set with zero and O1HY
is set at 0.1 F.
Setup Summary:Setup Summary:
FUNC=BASC
IN1=PT.DN
IN1U= F
DP1=1-DP
OUT=DIRT
O1TY=RELY
SP1L= 14 F
SP1H= 32 F
FUNC=BASC
IN1=PT.DN
IN1U= F
DP1=1-DP
OUT=DIRT
O1TY=RELY
SP1L=
14 F
SP1H=
32 F
User Menu:User Menu:
PB1=0 ( F )
O1HY=0.1 ( F )
PB1=0 (F)
O1HY=0.1
(F)
Cooling Control ExampleCooling Control Example
Figure 5.6Figure 5.6
RTD
Refrigerator
8 9
10
5
6
Mains
Supply
Mains
Supply
ON-OFF control
Direct Control Action
ON-OFF control
Direct
Control Action
O1
O2
A1
F
ETR-3400