Goldine Controls GL-235 Operation Manual

GL-235

Solar Pool Controller

Installation & Operation Manual

G

LD

C

LINE

ONTROLS

www.goldlinecontrols.com

Description

VVV

V

The GL-235 is a differential temperature control for solar heating of pools, spas, and hot tubs. It
provides differential temperature control with an adjustable, calibrated water temperature high limit.
Automatic nocturnal cooling (for pools that overheat in hot climates) and recirculate freeze
protection functions can be enabled/disabled via internal jumpers.

Input power can be either 115 or 240 VAC. The output controls a 24VAC automatic valve actuator.
For older systems with 12VAC valves, an internal jumper can be moved to select 12VAC output
operation. The GL-235 also has a high voltage output for controlling a filter pump or booster pump.

Specifications

Power: 105-130VAC, .5A 50/60Hz.

or

195-250VAC, .3A 50/60Hz

Output: Selectable low voltage 24VAC,

20VA, .85A or 12VAC, 20VA,

1.7A

SPST-NO isolated contact
115VAC 1HP
240VAC 2HP

Sensors: 2 required (thermistor,
10Kohm @ 25C/77ºF).

Differential: on at 4ºF, off at 1.5ºF

Desired
Pool
Temp.: 70-104ºF calibrated scale or So-

lar Off, 75 (24ºC) -104ºF (40ºC)
on some models

Recirculate
freeze: On at <40ºF (4.5ºC), off at >

42ºF (5.5ºC), Enabled via
jumper

Nocturnal
cooling: On when collector 8ºF less than

pool and pool hotter than limit,
off when collector 3ºF less than
pool or pool cooler than high
limit. Enabled via jumper

Installation

Mounting

The GL-235 is designed for outdoor use. Mount the box vertically with the knockouts facing
downward. For safety, the GL-235 must be a minimum of 5 feet (horizontally) from the pool or
spa.

Power input

Turn off power at circuit breaker before wiring. Remove the internal panel to expose the wiring
connections. Either 115VAC or 240VAC can be used. Refer to the input wiring diagram (Figure 1)
on next page. WARNING: Applying 240VAC to the 120VAC input terminals will cause

permanent damage to the control.

Grounding

Refer to NEC and local codes for specific grounding requirements. In general, a separate ground
conductor must be run to the ground terminal on the pool service panel.

Low Voltage (LV) output: Solar Valve

The GL-235 controls a single valve. In most applications this is the solar valve, which diverts water
through the collector panels or through the normal pool loop depending on conditions.

2 11

All controls are shipped with the output voltage set to the industry standard 24VAC. To use the GL-

g

235 with older 12VAC valves, move jumper J4, located on the right side of the circuit board.

The GL-235 provides two different types of connections to the pool/spa actuators. For older
actuators with no wire end connector, a 3 position terminal block is used. Connect the wires to the
proper terminal block according to the color code shown in Figure 4. If the valve operates opposite
to the way it is supposed to, reverse the red and white wires. Be careful not to short the valve output
wiring. The GL-235 is fused and shorting the output will require replacing the fuse.

For newer Goldline, Compool, Hayward, and Jandy actuators (with wire end connectors), two 3-pin
connectors are supplied. Plug the actuator into one of the two 3 pin connectors as shown in figures
2 or 3. If the valve operates opposite to the way it is supposed to, disconnect and plug into the other
connector.

High Voltage (HV) output: Booster Pump

The GL-235 can control a high voltage booster pump in addition to the normal low voltage solar
valve. Note the high voltage relay contacts are isolated so that the booster pump can be run on a
separate circuit, as required by many local codes. The GL-235 turns on, the valve output will operate
first, and then the HV relay will operate 30 seconds later.

High Voltage (HV) output: Timeclock Override

The GL-235 can also be used to override the filter pump timer. This is very important if recirculate
freeze protection or nocturnal cooling functions are being used. Also, this function can be used on
systems where the system should operate whenever solar heat is available, regardless of the timer
settings. The HV relay will operate approximately 30 seconds after the LV relay.

Sensor Mounting and Wiring

Most installations use a PC sensor to measure the pool temperature and another PC sensor to measure
the solar temperature. Alternatively, an SC-¼ sensor can be screwed into the pump strainer basket
to measure the pool temperature.

Pool Sensor: Drill a 3/8” (or 5/16”) hole in the PVC pipe. Remove burrs around the hole. Check
that the O-ring is seated on the PC sensor and then insert sensor into pipe. Tighten hose clamp over
the sensor to make a seal—DO NOT OVERTIGHTEN.

Solar Sensor: Use a screw or silicon adhesive to attach the sensor near the solar collector array.
The sensor does not have to be attached to the collectors. It is only important that the sensor be
exposed to the same sunlight as the collectors. Additionally, the underside of the sensing element
may be covered with silicon to minimize wind cooling.

Other 10K ohm Goldline sensors may be substituted. Wire should be twisted pair 20AWG. Sensor
wiring run outdoors must be rated for outdoor use and ensure that the wire connections are
protected from the weather. Do NOT run sensor wires in the same conduit or multiconduc-
tor cable as the valve actuator wires or any 120/240V circuit. For long runs or runs near
other electrical wiring use shielded cable (Belden 8428 for outdoor use). Ground the shields to the
GL-35/LV ground screw.

EARTH

GROUND

240 VAC

input power

high

voltage

output

{

EARTH

GROUND

115 VAC

input power

Figure 1

310

high

volta

output

{

e

Freeze Protection

If you are relying on the collectors naturally draining to provide freeze protection, it is very important
that you use a

non-positive seal valve or drill a hole (1/8"--1/4") in the diverter of a positive

seal valve to allow the collectors to drain. Alternatively, the GL-235 control can provide

recirculate freeze protection. If enabled, when the GL-235 senses a freeze condition at the collector
sensor, it will allow circulation of relatively warm water from the pool to the collector panels.

The GL-235 will allow recirculation when the collector temperature falls below 40ºF and will stop
circulation when the collector temperature rises above 42ºF. While this type of freeze protection
has proven to be adequate in relatively mild climates, it is extremely important that the sensors be
properly placed and that the homeowner realize that the system is unprotected in the event of a power
failure. Recirculate freeze protection is NOT recommended in climates where freezing temperatures
are common or last for extended periods.

Goldline strongly recommends the use of GC-3 freeze snap switches if freeze protection is being
utilized. Snap switches should be wired in series with the collector sensor. Placement of the snap
switches at the coldest point of the collector array and exposed plumbing will help assure that freeze
protection starts early enough to protect the system.

The GL-235 is shipped from the factory with recirculate freeze protection disabled (the jumper is
present but installed on one pin only). To activate recirculate freeze protection, install the jumper
across both pins marked “RECIRC”, located near the top right of the main circuit board.

If recirculate freeze protection is to be used on a GL-235, either:

•

The filter pump must be set for continuous operation

or

•

The GL235 High Voltage Output must be wired for Timer Override function.

Nocturnal Cooling

The GL-235 has nocturnal cooling logic, which can be enabled/disabled via a jumper on the main circuit
board. During nighttime hours, when enabled, the GL-235 will circulate relatively warmer water from
the pool to the collector panels, thus cooling the pool over time. The GL-235 will circulate water
when the collector temperature AND the pool temperature is hotter than the high limit setting.
Circulation will stop when the collector temperature is 3ºF less than the pool temperature OR the
pool temperature is cooler than the high limit setting. The GL-235 is shipped from the factory with
nocturnal cooling disabled (the jumper is present but installed on one pin only). To activate nocturnal
cooling, install the jumper provided onto the two pins marked “COOLING” located near the top
right of the main circuit board.

If nocturnal cooling is to be used, either:

•

The filter pump must be set for continuous operation

or

•

The GL-235 High Voltage Output must be wired for Timer Override function.

4