Time Gaurd TPT88 Installation & Operating Instructions Manual

UNDERFLOOR HEATING

CONTROLLER

Cat. No TPT88

INSTALLATION & OPERATING INSTRUCTIONS

1

Continuously
OFF indicator

Normal
operating
(timed)
mode

Probe
failure
indicator

Output to
underfl oor
heating ON

Periods of
comfort
temperature

Programme
overview
display

Continuous

control of

comfort

temperature

Day

indicator

(day 1 =

Monday)

Programme

number

24 hour time

display (also

indicated

copy in

Programming

mode)

Push to

illuminate

display

Temperature display - shows under-fl oor temperature

(except when Comfort and Economy temperatures are being set)

Fig. 1

Introduction

The TPT88 is a combined temperature and time controller for
electric underfl oor heating. It is rated at 16A (3.68kW). The
unit controls to a fully adjustable comfort temperature during
programmed ON times and to a fully adjustable economy
temperature during OFF times. It does this by using the signal
from an underfl oor probe (included). Both the economy and
comfort temperatures can be set to a minimum of 7°C to give
frost protection.

The large LCD display can be back lit if required at the press
of a button. The display reverts to normal 15 seconds after the
button is fi rst pressed.

Connections

The TPT88 must be used with the temperature probe provided.
Connections are made to the unit according to the following
diagram.

2

Fig. 2

Siting

The TPT88 should not be installed in a wet area such as a
bathroom or shower area. Further instructions are given in the
Thermolay Cable and Mat instruction leafl et.

Installation

The installation should be carried out by a competent person
following the latest I.E.E. wiring and local authority regulations
in the UK or the relevant wiring and local authority regulations
in other countries.

The TPT88 underfl oor heating controller is designed to fi t onto
either a BS4662 recessed single box or a BS5733 surface mount
single box. The minimum box depth required is 32mm. The
ideal mounting height is at eye level for the shortest person
who is likely to need to programme the unit. For details of the
installation of the temperature probe and heating cable or mat
see the Thermolay instruction leafl et.

Fig. 3 Fig. 4

Switch OFF the mains to the controller. Remove the front of the
thermostat by using a small screwdriver in the slot as shown in Figure 3.

Cut the cable tails of the temperature probe and heating mat or cables
to length and strip sleeving and insulation as required. Identify the
wires and locate according to fi gure 2. Supply cable with a minimum of

2.5mm
form the cables.

Offer the back plate up to the wall box forming the cables as required,

2

must be used. Tighten the screw terminals onto the wires and

3

fi nally locating and tightening up the fi xing screws supplied as shown
in Figure 4.

Snap the front of the thermostat back into position on the back plate.
To test the unit is operating set the temperature to 30ºC as described

in the section “Timed override for Two Hours“. After a few seconds the
Heating ON indicator will show.

Wait for a one hour for a wood underfl oor or up to 5 hours for an
uninsulated concrete fl oor (the warm-up time for uninsulated concrete
will be substantially reduced when the moisture has been driven out
of the concrete during the fi rst few heating cycles) and feel if the fl oor
starts to warm. If it does not, check the connections and carry out the
checks on the mat or cable installation instructions.

Earthing

The TPT88 itself does not require to be earthed. The screen around the
fl ying lead (cold cable) from the Thermolay mat must be earthed to the
box terminal. This also applies to the screen at each end of the Thermolay
cablee, both of which must be earthed in the same way.