5
Slow Acting Zone Valves with Thermal Motors
When the DIP switch is set to
Thermal Motor, the 368 assumes that slow acting zone
valves with thermal actuating motors are connected to the zone relays. With slow acting
zone valves, the 368 allows a 3 minute period for the first zone valve to open before the
Heat Required light is turned on. The total operating time for the zone relays is also
increased by an extra 2 minutes. This helps compensate for the longer opening versus
closing time of the slow acting zone valves. Once the last zone relay is turned off, the 368
purges the boiler for one minute by signaling to the House Control to turn off the boiler
and keep the system pump operating.
UNOCCUPIED (NIGHT SETBACK)
The 368 can be switched into UnOccupied mode through the built in 24 hr. Timer or by
closing an external switch or timer relay wired between the terminals
UnO Sw — Com Sen
(11 & 13) on the control.
24 hr. Timer
The 368 has a built in 24 hr. Timer which can be used to set a single UnOccupied event
during a 24 hour period. The 24 hr. Timer is activated by pushing the
Start button at the
desired starting time for the UnOccupied period. The duration of the UnOccupied period
is then set using the
UnOccupied Duration dial. Once the Start button is pushed, the Timer
Active light is turned on and the 368 enters the UnOccupied mode each day at the same
starting time. The 24 hr. Timer can be deactivated by pressing the
Start button again. A
new UnOccupied period starting time can be selected by repeating the above procedure.
Note If an external switch is closed between the terminals
UnO Sw — Com Sen
(11 & 13), the 24 hr. Timer is disabled. An external UnOccupied switch and the 24
hr. Timer should not be used at the same time.
UnOccupied Switch Input
A switch or external timer with a dry relay contact output can be wired between the
terminals
UnO Sw — Com Sen (11 & 13) on the 368. When the switch or relay contact
is closed, the 368 registers an UnOccupied signal. A tekmar Timer 031 is available which
can be programmed to provide individual UnOccupied schedules for each day of the week
with up to two separate UnOccupied events per day. For more information on the Timer
031 see the Data Brochure D 031.
UnOccupied Temperature
When the 368 is in UnOccupied mode, the
UnOccupied light is turned on and the
UnOccupied dial is used to set the desired temperature within the UnOccupied zones.
Note If the RTU dial for an UnOccupied zone is set below the
UnOccupied dial, the 368
continues to use the RTU dial as the desired temperature within that zone.
Individual Zone Selection
The DIP switch on the 368 is used to select which zones are switched into UnOccupied
mode. If the DIP switch for a specific zone is set to
Occ / UnOcc, the zone is switched into
UnOccupied mode whenever the 368 receives an UnOccupied signal. If the DIP switch
for a specific zone is set to
Occ. only, the zone remains in the Occupied mode at all times.
Optimum Start / Stop
The Optimum Start / Stop feature is enabled when the DIP switch is set to
Optimum
Start. The 368 turns on the Optimum Start / Stop light each time the first zone enters its
delay or recovery period. Either the tekmar Timer 031 or the built in 24 hr. Timer on the 368
can be used with the Optimum Start / Stop feature. The tekmar Timer 031 has a DIP switch
which must be set to
Optimum Start / Stop in order to synchronize the timer with the 368
Optimum Start / Stop function. For more information on the Timer 031 consult the Data
Brochure D 031.
SYSTEM PUMP OPERATION
The
System Pump light is turned on every time the relay contact between terminals System Pmp — System Pmp (1 & 2) is closed. During
heating operation, the system pump operates whenever any zone requires heat. If thermal motor zone valves are used, the system pump
is held off for the first three minutes of the zone cycle in order to give the zone valve sufficient time to open. The system pump may also
operate for an additional purge period once the zone relays are turned off.
Pump / Valve Exercising
The zone valves, zone pumps and system pump are exercised to help prevent corrosion from building up and subsequently jamming
the equipment. Every three days the 368 runs through the following exercising procedure.
UnOccupied
70
°
F
(21
°
C)
40
(4)
100
(38)
UnOccupied
Off
Optimum Start
Occ/UnOcc
Occ. only
Zone 1
1
2 3
4
SCHD
Su
T I M E
AMPM
UNOCC
OVR
Sa
Mo
WeTh Fr
Tu
1
2
Zo
Out
12
11
UnO
Sw
Com
Sen
13
Occupied
Optimum Start / Stop
UnOccupied
Timer Active
24 hr. Timer
0
12 hrs.
24
6
18
• Dial the desired duration of the
UnOccupied period.
• Press start button at the time of day
you want the UnOcc. period to begin.
Timer Active light turns on.
Start
UnOccupied
Duration
0 = always Occupied
24 = always UnOccupied
Slow acting
zone valve
Off
Thermal Motor
