Issue
Satchwell CZU Mk 1 Zonemaster Controller requires replacement.
Environment
- Stand alone Fan Coil Unit Temperature Controller.
- Satchwell CZU Mk 1 Zonemaster Controller.
- CZU 1201
- CZU 1202
- CZU 1203
Cause
Obsolescence of Satchwell CZU Mk 1 Zonemaster Controller.
Resolution
OVERVIEW
Replacement of Satchwell CZU Mk 1 Zonemaster Controller with S-E Satchwell CZU Mk 4 Zonemaster Controller.
The CZU 4201 may be used to replace the following CZU Mk 1 Controllers :-
CZU 1201, CZU 1202, CZU 1203
N. B.
CZU 1201 Controllers provided an additional -9 to +9 V d.c. output enabling connection to peripherals such as the Satchwell NSU 1401 Night Set-back Override Unit, TSU 1402 Two Step Auxiliary Unit and SSU 1403 Signal Selector Unit.
CZU 1202 and CZU 1203 Controllers provided an additional -0.5 to +9 or -9 to +0.5 V d.c. output enabling connection to the Satchwell NSU 1401 Night Set-back Override Unit.
Additional outputs are not provided on the CZU 4201 Controller and in those applications where these are required then it will be necessary to consider an alternative Controller to the CZU 4201.
Details of the CZU 4201 may be viewed here.
CZU Mk 1 CONTROLLER - INTEGRAL TEMPERATURE SENSOR APPLICATION
CZU Mk 1 Controllers were manufactured with an integral Temperature Sensor.
Adjustment of setpoint was undertaken by means of a dial mounted on the front of the Controller housing.
This enabled the Controller to be installed in the controlled space.
The CZU 4201 however is intended to be installed either in or on a Fan Coil Unit casing or in a ceiling void.
No setpoint dial is mounted on the front of the CZU 4201 housing, thus precluding installation of the Controller in the controlled space.
Where an existing CZU Mk 1 Controller is installed in the controlled space and is to be replaced, it will be necessary to install an Adjustable Room Temperature Sensor in the controlled space in order that a CZU 4201 may be utilised as a replacement.
The S E STR 612 Adjustable Room Temperature Sensor may be utilised for this purpose.
Details of the STR 612 may be viewed here.
Any existing Actuator / Valve Body assemblies connected to the CZU Mk 1 Controller may be retained for connection to the CZU 4201.
CZU Mk 1 CONTROLLER - EXTERNAL TEMPERATURE SENSOR APPLICATION
In some instances an existing CZU Mk 1 Controller may have been installed with its integral Temperature Sensor disabled.
In such instances a remote Satchwell Adjustable Room Temperature Sensor such as the DRT 3451, or a remote Satchwell Duct Temperature Sensor from the DDU range of Sensors may have been installed and connected to the Controller..
Any existing remote Satchwell Temperature Sensors may be retained for connection to the CZU 4201.
Should the remote Satchwell Adjustable Room Temperature Sensor require replacement then this may be replaced by an S E STR 612 Adjustable Room Temperature Sensor.
Details of the STR 612 may be viewed here.
Should the remote Satchwell Duct Temperature Sensor require replacement then this may be replaced by an S E STD 670 Duct Temperature Sensor.
