Myron L 729II User Manual

Page 42

Set Point Conversion (SPC) / Reversing Set Point

The Myron L Company ships the Temperature controller

configured to Alarm/control when the temperature is TOO HIGH. If

the configuration is correct for your requirements skip to

Temperature Set Point Adjust.

As many uses require the temperature to be controlled by the

use of a heater or chiller, the TPO Module may be configured

to maintain an elevated or lowered temperature as required.

To reverse the set point/relay operation:

1. Locate the SPC on TP/TPO circuit board. See figures

III.D.8 & III.D.14.

2. Remove Jumpers.

3. Reinstall Jumpers 90° as shown in figure III.D.15.

FOR TEMPERATURE MODULE

Temperature Set Point Adjust

1. Ensure the SCO Module Set Point control is set

to FULL CCW position. For location see figure III.D.7.

2. Press BOTH the Temperature Select switch and

the Set Point switch on the front panel.

3. Adjust the TP/TPO Module Set Point Two (SP2)

to temperature as desired. See figure III.D.9.

Hysteresis is fixed at ~±6°C unless Special Ordered with

adjustable control.

Hysteresis with adjustable control is variable from ±0.6 to 6°C.

CAUTION: Adjusting the hysteresis too narrow may cause the

alarm to fluctuate (on-off) due to temperature variations causing

the relay to chatter. This condition is to be avoided, it may

damage the heater, chiller, etc. and will eventually damage the

relay.

REASSEMBLY

1. Carefully reinstall the front panel, bottom first.

Ensure no wires have been pinched between

enclosure and front panel.

2. Reinstall the screws and tighten.

3. To operate, turn power ON.

Figure III.D.14

INC

TEMP

CONTROL

HARNESS

DETAIL OF SET POINT CONVERSION (SPC)

ON TP/TPO MODULE AS CONFIGURED

WHEN SHIPPED FROM THE MFR.

SET POINT

CONVERSION (SPC)

DEC DEC

SPC

Figure III.D.15