Application Brochure

A 152-1
In North America: tekmar Control Systems Ltd., Canada
tekmar Control Systems, Inc., U.S.A.
Head Office: 4611 - 23rd Street
Vernon, B.C. Canada V1T 4K7
Tel. [phone] Fax. [phone]
All specifications are subject to change without notice.
Printed in Canada on recycled paper.
Product design, software and literature are Copyright © 1993 by:
tekmar Control Systems Ltd. and tekmar Control Systems, Inc.
Printed in Canada on recycled paper by
Wayside Press Ltd. Vernon / Kelowna, B.C.
2
Operation
The Two Stage Setpoint Control 152 maintains a selected domestic hot water (DHW) tank temperature by staging a low/high fire boiler.
The target DHW temperature in this example is 140°F (60°C). The low fire burner and DHW pump are turned on when the water
temperature drops below 137°F (58°C) — Setpoint 1 setting at 140°F, differential at 6°F. The high fire burner is turned on when the
water temperature drops below 134°F (57°C) — Setpoint 2 setting at 137°F, differential at 6°F. (High fire off at 140°F, low fire off at 143°F)
Specifications
The following are minimum recommended specifications for the control in this application.
•The DHW temperature shall be maintained within the programmed differential range based on the programmed setpoint
temperature.
•The DHW pump shall operate whenever there is a demand for hot water.
•The control shall be able to stage a low/high fire boiler to maintain DHW temperature.
•The control shall be able to display and adjust the setpoint temperature, differential and time delay of each stage.
•The control must be compatible with standard North American wiring hardware.
• The control shall be microprocessor-based and have two SPST internal relays with 10 amp (resistive) isolated contacts for outputs.
• The control shall be able to display the setpoint, differential and delay on either stage while the device is operating.
• The installation location must be maintained within the ambient temperature and humidity ranges specified in the D 152 Brochure
for this application, with the installer ensuring that the control and its wiring are isolated and/or shielded from strong sources
of electromagnetic noise.
•The control shall continuously monitor its sensor and provide an error message upon sensor or wiring failure.
•The control components required from tekmar are a Two Stage Setpoint Control 152 and one Relay 003.
Two Stage Setpoint Control 152 Adjustment Range Recommended Initial Setting
Temperature Display -85 to 302°F (-65 to 150°C)
Setpoint 1 -40 to 239°F (-40 to 115°C)
Differential 1 1 to 40°F (1 to 22°C)
Time Delay 1 0 to 19 min. 50 sec.
(10 second increments)
Operating Mode 1 Heating/Cooling Heat
Setpoint 2 -40 to 239°F (-40 to 115°C)
Differential 2 1 to 40°F (1 to 22°C)
Time Delay 2 0 to 19 min. 50 sec.
(10 second increments)
Operating Mode 2 Heating/Cooling Heat
Settings
Two Stage Setpoint Control 152 DIP switch setting for this application.
On
1
Off
2 Sensors
Additional Information
• For control installation and testing instructions see Brochures D 001 and D 152.
• For other control applications see Application Register A 000.
• For control theory and system integration details see Essays E 001 and E 002.