Install Instructions

ManualsBrandsTekmar ManualsHeating SuppliesRoom Temperature Unit (RTU)

STEP ONE REMOVING THE FRONT COVER

• Place a screwdriver or similar object into the small slot located in the top of the RTU.

• Push the screwdriver against the plastic ﬂap and pull the top of the front cover so that it pivots

around the bottom edge of the RTU.

STEP TWO MOUNTING THE RTU

• The RTU should be installed on an interior wall of the desired zone to be controlled. Do not mount the RTU in a location that may be

affected by localized heat sources or cold drafts. It may be necessary to install a draft barrier behind the enclosure in order to prevent

air from blowing through the wiring hole and affecting the RTU reading.

• Mount the RTU directly to the wall using two #6-1” screws. The screws are inserted through

the mounting holes and must be securely fastened to the wall. If possible one of the screws

should enter a wall stud.

STEP THREE WIRING THE RTU

Run 18 AWG or similar wire between the RTU and the

Com Sen-RTU

terminals on the control.

Insert the wires through the hole provided in the back of the RTU enclosure and connect them

to the RTU terminal block. Do not run the wires parallel to telephone or power lines. If the RTU

wires are located in an area with strong sources of electromagnetic noise, shielded cable or

twisted pair should be used or the wires can be run in a grounded metal conduit.

If installing a remote temperature sensor, connect its two wires also to the RTU terminal block

and cut the jumper in the RTU enclosure. For best accuracy, the RTU and the remote sensor

should be approximately at the same temperature.

STEP FOUR TESTING THE RTU

A good quality test meter capable of measuring up to 5000 kΩ ( 1 kΩ = 1000 Ω) is required to

measure the sensor resistance. In addition to this, the actual temperature must be measured

with either a good quality digital thermometer or if a thermometer is not available, a second

sensor can be placed alongside the one to be tested and the readings compared.

First measure the room temperature using the thermometer. The RTU must be disconnected from the control before it is tested. Turn

the RTU dial to 70°F (21°C). Measure the resistance of the RTU by touching the test leads on the wires running to the RTU. Reverse

the leads and measure the RTU resistance again. The lower “Ohm” reading is the combined resistance of the dial and the sensor, and

the higher “Ohm” reading is the resistance of the sensor alone.

Using the chart below, estimate the room temperature based on the sensor only (highest) resistance measurement. Compare the sensor

temperature measurement with the thermometer reading. If the sensor temperature is signiﬁcantly above the thermometer reading, the

wiring may be shorted, moisture may be in the sensor or the sensor may be defective. If the sensor temperature is signiﬁcantly below

the thermometer reading, there may be a broken wire, a loose connection or a defective sensor.

If a defective sensor is suspected, ﬁrst check the wiring from the RTU to the control and then

measure the sensor resistance directly at the RTU terminals using the above procedure.

STEP FIVE INSTALLING THE FRONT COVER

• Align the hinges on the bottom of the front cover with the bottom of the RTU mounting base.

• Pivot the front cover around the bottom hinges and push the top against the mounting base

until it snaps ﬁrmly into place.

01/09

- Data Brochure

Room Temperature Unit (RTU) 054

Installation

Top view of RTU

Small slot for

screwdriver

D 054

Installing the

front cover

48 50 52 54 56 58 60 62 64 66 68 70 72 74 76 78 80 82 84

9 10 11 12 13 14 16 17 18 19 20 21 22 23 24 26 27 28 29

20.8 19.7 18.7 17.7 16.8 15.9 15.0 14.3 13.5 12.8 12.2 11.5 10.9 10.4 9.8 9.3 8.8 8.4 7.9

Temperature

Resistance (kΩ)

°F

°C

The tekmar Room Temperature Unit (RTU) 054 consists of a temperature sensor and

an adjustable dial which is used to set the desired indoor temperature. The RTU 054 dial

has a temperature range from 40 to 100°F (4 to 38°C). In cases where a restricted

temperature range is required, the dial rotation can be limited using limit pins supplied

with the RTU. A 10K temperature sensor (e.g. 071, 072 etc.) can be mounted remote

from the RTU. This RTU does not work with older tekmar controls. If the RTU is to be

mounted on a 2" x 4" electrical box, an Adaptor Plate 007 is available for use.

#6-1" screws

RTU terminals

Wall Stud

To control

terminals

(Com Sen — RTU)

Jumper

Mounting the RTU

Summary of content (2 pages)

PAGE 1
- Data Brochure D 054 01/09 Room Temperature Unit (RTU) 054 The tekmar Room Temperature Unit (RTU) 054 consists of a temperature sensor and an adjustable dial which is used to set the desired indoor temperature. The RTU 054 dial has a temperature range from 40 to 100°F (4 to 38°C). In cases where a restricted temperature range is required, the dial rotation can be limited using limit pins supplied with the RTU. A 10K temperature sensor (e.g. 071, 072 etc.) can be mounted remote from the RTU.
PAGE 2
Settings To set a desired temperature, turn the RTU dial until the temperature is seen in the display window. Temperature scales 70 The RTU is supplied with two temperature scales. The RTU comes with the °F scale displayed in the window. The °C temperature scale is located on the back of the °F scale. In order to change the scale to °C, remove the front cover, lift and pull the scale off the dial, ﬂip it over and replace it.