tekmar 370 House Control User Manual
Page 9
Copyright © D 370 -06/99
9 of 20
Fast Acting Zone Valves or Zone Pumps
If the
Thermal Motor DIP switch is set to Off, the 370 assumes that fast acting electric
motor zone valves or zone pumps are connected to the zone relays. The system pump
is therefore turned on as soon as the first zone relay is operated. One minute before the
last zone relay is turned off, the 370 purges the boiler.
Slow Acting Zone Valves with Thermal Motors
When the DIP switch is set to
Thermal Motor, the 370 assumes that slow acting zone
valves with thermal actuating motors are connected to the zone relays. With slow acting
zone valves, the 370 allows a 3 minute period for the first zone valve to open before the
system pump 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. For one minute after the last zone relay is turned off, the
370 purges the boiler.
COOLING OPERATION
When the DIP switch on the 370 is set to
Zone 1 Cooling, zone relay 1 can either be used
to enable an auxiliary cooling control system or to directly operate a central cooling unit.
Cooling Control (RTU is present)
If
Zone 1 Cooling is selected and an RTU or Indoor Sensor is connected to terminals Com
Sen — RTU 1 (5 & 6), the 370 can directly control a central cooling system using zone
relay
1. If an RTU is used, the desired indoor temperature is set using the RTU dial down
to 73
°F (23°C), but if an Indoor Sensor is used, the desired indoor temperature is fixed
at 77
°F (25°C). Zone relay 1 is allowed to turn on once the heating zones in the 370 have
been satisfied for at least 45 minutes, and is turned off whenever any zone requires heat.
The 370 varies the on time of zone relay
1 over a 30 minute cycle. As the cooling load
increases, the on time of the zone relay increases. In order to prevent short cycling, the
370 ensures that zone relay
1 remains on or off for at least 3 minutes.
Cooling Enable (no RTU)
If
Zone 1 Cooling is selected and there is no RTU or Indoor Sensor connected to terminals
Com Sen — RTU 1 (5 & 6), the 370 can enable an auxiliary cooling control through zone
relay
1. Zone relay 1 is turned on once the heating zones in the 370 have been satisfied
for at least 45 minutes, and is turned off whenever any zone requires heat.
UNOCCUPIED (NIGHT SETBACK)
The 370 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
Com Sen — UnO Sw
(11 & 12) on the control.
24 hr. Timer
The 370 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 set using the
UnOccupied Duration dial. Once the Start button is pushed, the Timer
Active light is turned on and the 370 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 then be selected by repeating the
above procedure.
Note:
If an external switch is closed between the terminals
Com Sen — UnO Sw (11
and 12), 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
Com Sen — UnO Sw (11 and 12) on the 370. When the switch or relay contact
is closed, the 370 registers an UnOccupied signal. If Optimum start/stop is selected, then
the UnOccupied operation will occur 12 hours later. 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 370 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
370 continues to use the RTU dial as the desired temperature within that zone.
UnOccupied
70
°F
(21
°C)
40
(4)
100
(38)
UnOccupied
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
SCHD
Su
T I M E
AMPM
UNOCC
OVR
Sa
Mo
WeTh Fr
Tu
1
2
Uno
Sw
12
11
Com
Sen
2
26
1
25
24
Com
1-2
Cooling Control
RTU
1
6
5
Com
Sen
C
RTU
2
26
1
25
24
Com
1-2
Cooling Enable
RTU
1
6
5
Com
Sen
C
NO RTU
Zone 1 Cooling
Zone 1 Heating
Fast acting
zone valve or
zone pump
Thermal Motor
Off
Thermal Motor
Off
Slow acting
zone valve
Operation