CONIFER SOLAR CONSULTING

Jon Klima, Owner
360 Trout Lane, PO Box 23, Guffey, CO 80820
Phone: 719 479-2281,  Email: jon.klima@gmail.com
In business for 37 years

 

• Article 27 - April/May/June, 1999

 

Novan DLP-20 Power/Relay Box Testing©

 

Every so often when someone wants to send me a Novan DLP-20 controller for repair, they ask if they need to send the box that contains the power supply and output relays. My standard reply is, if you have power at the digital display box, as evidenced by any of the LEDs being on, and you can make the relays operate properly, then there is no need to send the relay box. But how can you check those output relays? All you need are a couple of jumpers, a 120-volt test lamp, and the following test procedure:

 

First disconnect the red (DC +), black (ground), brown (relay RL2), white (relay RL2), and green (relay RL3 when present) wires from the display box connected to the power box terminal board. To check to see if relay 1 is working, jump ground to the RL1 terminal. You should see the relay 1 contacts transfer. To check for relay 2 operation, jump ground to the RL2 terminal. This should cause the relay 2 contacts to transfer.

 

Terminals Jumpered

Potable Pump

Spa Out

Div. Valve

Solar Pump

Ground to RL1

ON

OFF>

OFF

ON

Ground to RL2

OFF

OFF

OFF

OFF

Ground to RL1 & RL2

OFF

ON

ON

ON

Relay Test Table of Novan DLP-20

 

In addition to observing the contact movements on these relays, it is necessary to verify that 120 VAC power is being transferred to the output terminals on the 120 VAC terminal board. The table below lists those terminal pairs that should have 120 VAC across them (this is where the 120-volt lamp is used) for the three different jumper conditions.

 

Terminal Numbers

Function

Wire Colors

Green

White/Neutral

Black

1-3

120 VAC Power In

1

2

3

4-6

DHW Pump Power Out

4

5

6

7-9

Diverting Valve Power Out

7

8

9

10-12

Spa Pump Power Out

10

11

12

13-15

Solar Pump Power Out

13

14

15

Novan 2011 Controller Terminal and Wire Identification

 

The connections to the power terminal board are clearly marked and should not present any problems as long as you remember that H stands for high (the black wire) and L stands for low or neutral (the white wire). The green wire on all power cords should be connected/grounded at the appropriate screws on the metal box next to where the wires are brought into the box.

 

The older sister controller of the Novan DLP-20 is the Novan 2011 controller. This unit contains the power source, output switching relays, and the logic and digital display all in one box. The connections to be made to the 2011 power terminal board are labeled 1 - 15 and it is not clear which wires go where. These connections are noted in the table below.

 

The above data are taken from a published Novan Maintenance manual, controller box markings, and printed circuit board markings and are believed to be correct. If you find any errors or wish to add anything to the above discussion, please contact me at (303) 838-4107.

 

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