tekmar 370 House Control User Manual

Page 9

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)



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)



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

°F

(21

°C)

40
(4)

100

(38)

UnOccupied

Occupied

Optimum Start / Stop

UnOccupied

Timer Active

24 hr. Timer

12 hrs.

• 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

T I M E

AMPM

UNOCC

OVR

WeTh Fr

1
2

Uno

Com

Sen

Com

1-2

Cooling Control

RTU

Com

Sen

RTU

Com

1-2

Cooling Enable

RTU

Com

Sen

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