Setting The Control To Restricted Adjustment Mode; Adjustment Behavior In Restricted Adjustment Mode; Repositioning The Jumper To Restrict Control Adjustment - Penn A421 Series Installation Manual

Figure 12: Adjustment behavior in Restricted Adjustment mode

Setting the control to Restricted Adjustment mode

To set up the restricted adjustment feature, complete the following steps:
1. To make sure that the A421 is not in restricted mode, position the jumper on both pins. See
Figure 13.
2. Select the OFF and On values that define the application's required control band (Figure 12).
3. Change the HtS and LtS temperature values to define the restricted adjustment range (Figure
12).
4. Disconnect power to the control and reposition the jumper to one pin (Figure 13). Reconnect
the power.
Figure 13: Repositioning the jumper to restrict control adjustment
Control adjustment is now restricted to changing only the OFF value, which shifts the On and OFF
control band within the restricted adjustment range defined by HtS and LtS (Figure 12).
Note: To completely restrict and lockout all user adjustment on the control, set the HtS value
equal to the On or OFF value and the LtS value equal to the OFF or On value. Then the (On to
OFF) control band is equal to the restricted adjustment range, LtS to HtS, and the OFF value
cannot be adjusted in the restricted mode.
20 A421 Series Electronic Temperature Controls with Off-Cycle Defrost Installation Guide