tekmar 157 User Manual

- Data Brochure

Difference Setpoint Control 157

D 157

06/10

The Difference Setpoint Control 157 is designed to operate a variable speed pump to transfer heat from a heat source to a storage tank. Varying the speed of the pump provides fast and accurate temperature control to maintain the target temperature difference (T). Additional minimum and maximum setpoints turn off the pump when heat transfer is no longer desirable. Potential applications include using solar collectors or a wood boiler as a heat source.

Additional functions include:

120 V (ac) powered pump outputs

• Second On/Off pump with 4 modes of operation

• Optional auxiliary sensor input to be used in heat dump and heat supplement modes

• Freeze Protection

• Displays total amount of energy transfer in BTU or kWh

• Certified to CSA and UL standards for use in the USA and Canada

•

NEW Solar Sensor 085 immersion type sensor included!

•

VIEW

Item

ΔT

Black

Red

Blue

Green

Input

Solar Sensor

Included

Input

Universal Sensor

Included

Input

Universal Sensor

Optional

Input

Demand

Signal

Input

24 V (ac)

Power Supply

Input

120 V (ac)

Power Supply

Output

On/Off

Pump

Output

Variable

Speed Pump

Ground

How to Use the Data Brochure

This brochure is organized into three main sections. They are: 1) Sequence of Operation, 2) Installation, and

3) Control Settings

Table of Contents

User Interface ...............................................................2

Display .......................................................................... 3

Symbol Description .......................................................3

Sequence of Operation .................................................4

Section A: General ................................................... 4

Section B: Modes of Operation ................................4

Section C: Targets and Differentials ......................... 5

Section D: Control Features .....................................6

Section E: Energy Calculation .................................. 7

The Control Settings section of this brochure describes the various items that are adjusted and displayed by the control. The control functions of each adjustable item are described in the Sequence of Operation.

Installation ....................................................................8

Control Settings ......................................................... 10

DIP Switch Settings ................................................ 10

VIEW Menu ............................................................ 11

ADJUST Menu ....................................................... 12

Test Routine................................................................ 14

Error Messages .......................................................... 15

Technical Data ............................................................ 16

Limited Warranty ....................................................... 16

User Interface

The 157 uses a Liquid Crystal Display (LCD) as the method of supplying information. Use the LCD in order to set up and monitor the operation of your system. The 157 has three push buttons (Item, ▲, ▼) for selecting, viewing, and adjusting settings. When programming the control, record settings in the Adjust menu table which is found in the second half of this brochure.

Item

The selected item will be displayed using the segments available in the screen. To view the next available item, press and release the Item button. Once you have reached the last available item, pressing and releasing the Item button will return the display to the first item.

Item

Adjust

To make an adjustment to a setting in the control, press and hold simultaneously for 1 second all three (3) buttons. The display will then show the word ADJUST in the top left corner. Select the desired item using the Item button. Finally, use the ▲ or ▼ button to make the adjustment.

Item

Display

Menu Field

Displays the

current menu

Item Field

Displays the current

item selected.

Symbol Description

Number Field

Displays the current value of the selected item

Status Field

Displays the current status of the relay.

Buttons

Selects Menus, Items and adjusts settings

Item

ΔT

SOURCE

MODE

FLOW

DIFF

ENERGY

Delta T

Displays the temperature difference between the source and storage sensors.

Source

Displays the temperature at the source sensor.

Mode

Displays the modes of operation for the on/off pump, P2.

Flow

Displays the maximum flow rate of the variable speed pump.

Differential

Displays any differential.

Energy

Displays the total number of BTU’s or kWh’s accumulated by the control’s energy calculation.

STORAGE

AUXILIARY

MINMAX

TARGET

OUTPUT

Storage

Displays the temperature at the storage sensor.

Auxiliary

Displays the temperature at the auxiliary sensor.

Minimum and Maximum

Displays the min and max sensor temperatures.

Target

Displays any target.

Fluid Constant K

Used to calculate heat transfer. Look up fluid constant in this data brochure.

Output

Displays the % output of variable speed pump. Each bar represents 20% output.

FREEZE

PROTECTION

Freeze Protection

Displays the status of the freeze protection function of the control.

Pump

Displays the status of the variable speed (1) and secondary (2) pump.

°F,°C, min,

% ,BTU, kWh,

GPM

Units of Measurement

Demand Pointer

Displays if a demand is applied to the control.

Sequence of Operation

Section A – General

Powering Up The Control

When the Difference Setpoint Control 157 is powered up, all segments are displayed in the LCD for 2 seconds, and then the type number is displayed for 2 seconds. Next,

Source Sensor

Heat

Source

Pump

Heat

Storage

Sensor

the software version is displayed for 2 seconds. Finally, the control enters into the normal operating mode and by default the LCD displays the current T temperature.

Turn On

Variable Speed Pump

A manufacturer approved wet rotor circulator is connected to the 157 at the back of the control (see Table 1 for approved pumps). The 157 increases or decreases the power output

When the variable speed pump turns on, it will operate at 100% output for an adjustable amount of time before operating at a variable speed starting at the minimum pump speed setting.

to the circulator to vary the speed and maintain the target difference setpoint temperature (∆T) between the source and the storage sensors. As the ∆T increases, the pump speed increases and as the ∆T decreases, the pump speed decreases. The current % output of the variable speed pump is displayed in the view menu.

Turn Off

If the temperature difference falls below the ∆T target less the ∆T differential, or below 1°F (0.5°C), the variable speed pump will operate at the minimum pump speed for 2 minutes before shutting off. The minimum off time for the variable speed pump is fixed at 2 minutes.

Table 1: Manufacturer approved pump models

Grundfos (F) Taco B & G Armstrong Wilo

15-42 15-58 26-64 43-75 003 007 0010 0012 NRF 9NRF 22NRF ** *** ** *** 25BU 30 50 * ** *** S21FX 17FX 30F

Astro Star S16FX Star

*Speed 1,**Speed 2, ***Speed 3 These circulators have been tested and approved by the manufacturer for use with tekmar variable speed electronics.

Section B – Modes of Operation

The 157 has a second 120 V (ac) powered output wired through the back of the control for an on/off pump. The second pump has 4 adjustable modes of operation depending on the application.

Mode Off

is for applications where the second pump is not used. The second pump relay is non-operational. Refer to application A157-1.

Mode 1 Heat Exchanger is for applications where the

heat exchanger pump is needed to transfer heat between an external heat exchanger and the storage tank. The heat exchanger pump relay will operate whenever the variable speed pump is above 0% output. Refer to application A157-2.

Variable

Speed Pump

Heat Exchanger

Pump

Heat

Storage

Mode 2 Heat Supplement

is for applications where the heat supplement pump transfers heat from a supplemental heat source (i.e. back-up boiler) to maintain the storage tank above the minimum storage target. The auxiliary sensor is optional in this mode. Install the auxiliary sensor in the upper portion of the storage tank. Refer to application A157-3.

If the boiler is not flow activated, the heat supplement pump output could provide a heat demand to another controller to turn on the boiler.

In this mode, the minimum on and off time for the heat supplement pump is fixed at 30 seconds.

Supplemental

Heat Pump

Variable

Speed Pump

Heat

Storage

Mode 3 Heat Dump is for applications where an

alternative heat sink can be utilized when the storage tank and collector are both above their maximum target. The variable speed pump turns off when the tank exceeds its max setpoint. The heat dump pump turns on when both the tank and collectors exceed their max setpoints. If during a heat dump the storage temperature falls below its maximum targets less differential, the heat dump pump relay is turned off and the variable speed pump is allowed to operate normally. The auxiliary sensor is optional in this mode. Install the auxiliary sensor in the heat dump. Refer to application A157-4.

Mode 4 Booster Pump

is for drain back applications

where a booster pump is used to overcome high head upon system startup. When the T rises above the T target, the control turns on the booster pump and operates the variable speed pump at 100% output. After an adjustable time, the control turns off the booster pump and operates the variable speed pump above the minimum pump speed setting. Refer to application A157-5.

Variable

Speed Pump

Heat Dump

Pump

Heat

Storage

Booster

Pump

Variable

Speed

Pump

Heat

Storage

Table 2: Second Pump Mode Summary

MODE NAME DESCRIPTION APPLICATION

Off Off Only the variable speed pump is operational. A157-1

3 Heat Dump

Heat Exchanger

Heat Supplement

Booster Pump

Heat exchanger pump operates together with the variable speed pump. A157-2

Heat supplement pump operates independently of the variable speed pump to maintain the storage tank at the minimum storage target.

Heat dump pump operates when the storage and source temperatures rise above their max targets to dump excess heat from the collectors.

Booster pump operates together with the variable speed pump at start up for an adjustable amount of time to overcome high head in drain back systems.

A157-3

A157-4

A157-5

Section C: Targets and Differentials

MAXIMUM SOURCE TARGET

(Mode = off, 1, 2, and 4) If the source temperature rises above the maximum source

target, the variable speed pump is turned off. In a drain back system, turning off the pump allows the fluid to drain back into a separate tank which protects the collectors from overheating. Ceasing operation may also protect equipment like the pump impeller from damage. The pump remains off until the source temperature falls below the maximum source target less differential.

Table 3: Outlines when the variable speed pump and heat dump pump are allowed to operate normally in mode 3.

Table 3 Scenario

1234

Max Storage Setpoint below Max Source Setpoint below below

above above

below

Variable Speed Pump on off off on

Heat Dump Pump off off on off (Mode = 3, Heat Dump) In order for the heat dump pump to turn on, the storage

temperature must be above the Maximum Storage Setpoint and the source temperature must be above the Maximum Source Setpoint. If the source or storage temperatures fall below their maximum targets less differential, the heat dump pump is turned off. The variable speed pump operates normally whenever the storage temperature falls below its maximum setpoint less differential. This setting ensures

MINIMUM SOURCE TARGET

If the source temperature drops below the minimum source target, the variable speed pump is turned off. In a drain back system, turning off the pump allows the fluid to drain back into a separate tank which protects the collectors from freezing. The pump remains off until the source temperature rises above the minimum source target plus differential. This item is only available if freeze protection is turned off.

that the water being supplied to the heat dump is at least the Maximum Source Target temperature.

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