15
Enable-Off-Remote Contact Switch (SW1) —
The position of the Enable/Off/Remote contact switch is
ignored except when the “remote mode” control type is
selected. Refer to the Machine Control Methods section on
page 20 for more details. A selection for Machine Control
Method must also be made along with the correct position of
the Enable-Off-Remote Contact Switch. This switch is
installed in all units. It is a 3-position switch used to control the
chiller. When switched to the Enable position, the chiller will
be under its own control. When switched to the Off position,
the chiller will shut down. When switched to the Remote Con-
tact position, a field-installed dry contact can be used to start
the chiller. The contacts must be capable of handling a 24-
VAC, 50-mA load. In the Enable and Remote Contact (dry
contacts closed) positions, the chiller is allowed to operate and
respond to the scheduling configuration and set point data.
Emergency On/Off Switch (SW2) — This switch is
installed in all units. The Emergency On/Off switch should
only be used when it is required to shut the chiller off immedi-
ately. Power to all modules is interrupted when this switch is
off and all outputs from these modules will be turned off.
Energy Management Module (EMM) — The EMM
is available as a factory-installed option or as a field-installed
accessory. See Fig. 18. The EMM receives 4 to 20 mA inputs
for the temperature reset, cooling set point and demand limit
functions. The EMM also receives switch inputs for the field-
installed second stage 2-step demand limit and ice done func-
tions. The EMM communicates the status of all inputs with the
Touch Pilot module, and the controls adjusts the control point,
capacity limit, and other functions according to the inputs
received. See Table 10 for EMM board inputs and outputs.
CAUTION
Care should be taken when interfacing with other manufac-
turer’s control systems due to possible power supply differ-
ences, full wave bridge versus half wave rectification,
which could lead to equipment damage. The two different
power supplies cannot be mixed. Touch Pilot
™
controls use
half wave rectification. A signal isolation device should be
utilized if a full wave bridge rectifier signal generating
device is used.
Fig. 18 — Energy Management Module
221
221
221
221
100K
100K
100K
100K
100K
CH
17
CH
17
CH
16
CH
CH
18
CH
19
CH
20
CH
22
CH
21
CH
23
24 VAC
12 11
CH
11b
CH
12
CH
13
CH
14
CH
15
CH
1
CH
2
CH
3
CH
4
CH 5
CH 6
CH 7
SIO LEN
+ G -
+ G -
SIO LEN
J8
J7B
J7A
J6
J5
J4 J3 J2B
J2A
J1
CH
24
CH
25
CH
8
CH
9
CH
10
CH
11a
J9A
J9B
RED LED - STATU S
GREEN LED - LEN
(Local Equipment Network)
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